Need advice: Biamping vs. dual bridged monos

I am now the proud owner of two Classe CA-100 power amps. I had one, loved it, then saw another available at an excellent price and couldn't walk away without it. So now I've got two.

...But now I need some guidance. With two 2-channel amps, what is the best way to power my speakers (Magnepan 3.5 in stock form, no modifications)?

I could use the CA-100s in mono mode; in mono mode they are rated (per the manufacturer's specs) for 350 watts each into 8 ohms, or 600W into 4 ohms.

Or I could use them in stereo mode and bi-amp my Maggies.

Which method is generally regarded as the better method?

If I go with bi-amping, then I need to get a new preamp because my old Denon preamp has only one set of pre-outs. Or is there a suitable way around that too?

Any insight you all can provide is greatly appreciated. As you can tell, I didn't put a lot of planning and forethought into this, I just saw a great deal on a Classe CA-100 and couldn't walk away from it.

Bridging reduces the ability to drive low impedance loads; there should be material on this in the archives. If this is not a problem try it both ways and see for yourself. I used Y connectors when I bi amped with no problem or you could have another set of jacks installed or a pair of your current ones rewired. I doubt if your Denon is up to the level of the Classe or Maggies but if you like it use it. I personally would go with bi amping but YMMV.
Although I have no experience with the CA-100's, the Maggies are not that difficult a load, despite their power appetite and low impedance.

Tried to do some research on the CA-100's and found mixed results for bridging. By the specs, they should be capable and they are rated for bridged operation into 4 ohms. For best results, use XLR interconnects if possible because the amp becomes differentially balanced when bridged.

This assumes that they are actually bridged as opposed to being "parallelled", which is not always a safe assumption.

Wouldn't hurt to try.
biamp power needs are based on crossover frequency.
The 50:50 point is (around) 350hz. So, if the crossover is higher, the bass amp will run out of steam first...if the crossover is lower, the treble amp will have problems at the highest levels.

You could, and are probablly thinking to do a lo/ mid-hi split which would be just fine.
I have compared this several times with different amps, and universally I have preferred the Mono configuration with bi-wiring to running two Stereo amps.

I run two Pathos Classic One MkIII integrateds (reviewed) and always run them Mono when not using them with an active x-over (a special configuration which requires more channels of amplification, thus running them in stereo). Mono is almost always perceptually more pleasing due to the improved macrodynamics, often without harm to the definition and in some cases a nice improvement of definition.

I also have two Cambridge Audio Azur 840W amps, which are also configurable as stereo, dual mono or single mono. When using them in single mono mode the increase in dynamics and expansiveness of soundstage is considerable. Again, I always biwire to take full advantage of the amp/speaker interface.

Watch your cabling very carefully; pay especially close attention to the power cords used with the amps, as they have a huge impact on the amps' sound. In any system I establish the change of the two power cords on the Monos results in a big shift in the system's sound. Not only does conductor material (i.e. silver coated copper vs. solid copper) but total gauge have an influence upon the results.
are your speakers set up whereby you can biamp them easily? In other words, does the input connectors have two separate connectors for high and low that are jumpered? If yes, then disconnect the connectors and simply connect the amps accordingly. one 2-channel amp for the high input of each speaker and the other 2-channel amp for the low input of each speaker. This assumes that you will be using the internal passive crossovers in your speakers. If your speakers do not have the twin connectors as I mentioned previously, then biamping is not possible. But, most speakers are designed and constructed being capable of biamping this way. You will immediately notice better clarity. The amps will not have to work as hard driving high, mid bass and low end signals.

Thanks to everyone for your advice!

To answer Minorl's question: Yes, my speakers are set up for bi-amping. Each speaker has a pair of treble inputs and a pair of bass inputs. The speakers also come with a simple crossover box that is connected directly to these treble and bass inputs on the back of the speaker. Then, the user simply connects the speaker cable to the two inputs on the crossover box. But when bi-amping, I guess that I have to set this manufacturer's crossover aside and get a good active crossover. ...But I really don't know. I have no experience with crossovers, bi-amping, bi-wiring, etc. This is all new to me. That's why I need guidance. : )
You can still use the passive crossover that came with your speakers to biamp. You will need an extra set of interconnect cables and speaker cables to go from the amps to the crossover and from the crossover to the speakers. The speaker's owner's manual should describe this in detail. Your passive crossover "should" have a jumpered high and low output connectors similar to your speaker's jumpered high and low connectors. To biamp, turn everything off, disconnect the jumpers on the crossover and the speakers. Then connect both amp's inputs to the outputs of the pre-amp. use "Y" connectors if your pre-amp only has one set of output terminals. Then connect one amp's output to the high input of the crossover for the right and left speakers, and the other amp's output to the low input of the crossover for the right and left speakers. Then take the high outputs of the crossover and run those over to the high inputs of the right and left speaker and take the low outputs of the crossover and run those over to the low inputs of the right and left speakers. you will need one additional set of interconnect cables for the second amp and short speaker cables (four sets) from the amps to the crossovers of the speakers. Place the amps as close to the speakers as you can to minimize cable lenght. It is better to have as short speaker cables as possible (much more signal loss) than interconnect cables. you will then need four sets of speaker cables from the crossover outputs to the inputs of each speakers. Again, the crossovers should be sitting right next to or on each speaker, so the cable length should be really short. You will also find that with really short speaker cable lenghts, the type of speaker cable really will not effect the sound much. In other words, try 10 gauge Mogami before you spend a large amount on expensive speaker cables. 10 gauge Mogami is really good stuff and as I said, with really short lengths, it doesn't matter much. Use decent to very good interconnect cables.