Good AVR to Power B&W 683's

I have a Marantz 6005 AVR, it puts out 110 W per channel. Is this enough for the B&W 683's? I am thinking of getting the 683's over the 684's but would hate to have to buy a new receiver. thanks for any feedback.

You don't need a new receiver, just add a quality high current outboard amp if you feel your Marantz doesn't have the gusto to do a proper job of powering your B&W's.

I recently owned one of these Parasounds and it was a fine amp that seemed much more powerful than it's rated 125w/ch output.

Thanks for the input. Pardon my ignorance, but will this type of pre-amp work well for 3-way speakers, or is it better for 2-way?

...also, if I have 2 fronts, center channel, sub and 2 rears, (5.1 set-up) would I not need a 5-channel preamp?

Your receiver can easily handle the surround channels. Just find you a 3-channel, high current Parasound, Adcom, Emotiva, or other decent brand amp for the front L/R and center speakers.
Your Marantz is a good AVR that has the latest HMDI 1.4 and decoder capabilities - it also has a full set of pre-outs. Absolutely no reason to chnage this receiver. Get the B&W 683's over the 684's right now. The 683 is a much better speaker and you won;t regret it. If you feel your Marntz can't get the job done, then as others have pointed out, get a 2 channel power amp and use those L/R Pre-Outs on the Marantz. There are many fine models at 100-150 wpc under a $1000. Some brands were already mentioned to you. This will certainly be less than buying a new receiver. And a seperate 2 channel power amp will make those 683's sound better tghan the most expensive AVR ever could. Finally, whether a speaker is 3 way or 2 way, has no bearing on the type of pre-amp use. You'll be fine.