Audio Research LS16 MkII or LS25 MkI ?

I have a system that serves dual purpose (stereo music and 5.1 Home theater) and I want to introduce an audiophile Preamp with HT bypass into the chain so I can create a 'clean' stereo audio system. My sources are Cambridge Audio Stream Magic 6 and Sony BDP-s790 (for CD/SACD). The power amps are Bel Canto 1000M monoblocks and the speakers are Thiel CS7.

I am looking curretly at a used ARC LS16 MkII and a LS25 MkI and I am looking for opinions, recommendations, feedback an comments. The LS25 is slightly more expensive, but in a way that makes a difference to me.

Which one should I go with and why or under which circumstances?

Thank you for your comments.
These are very different sounding preamps. The LS16 mk2 uses the 6h30 tube while the ls25 mk1 uses the 6922. I currently own an LS25 mk2 which also uses the 6h30 tube. I had an original LS25 (mk1) for about a month before I bought my mk2. and I was not impressed with it. I passed on it My mk2 is a much better sounding pre. The LS16 mk2 is a better sounding pre. I would wait for a LS25 mk2 or buy the LS 16. Audio Research preamps have come along way in the last 10 years or so.
Thank you for your feedback.

What if we added an LS26 to the mix?
I have not heard the LS26. I have heard the LS27 at my dealer and was very impressed. I would definitely go for the LS26 over an original LS25 or an LS16. But I don't know how good a match an Audio Research preamp will be with Bel Canto amps. I have an Audio Research amp. I would see if you could borrow a ARC preamp just to see if it is a good match.
Thanks Lostbears.

The more I dig, the more I read, the more questions I have.

I have to ask about another comparison next (new thread), where the dollars are at least equal, if the approach is not.
I don't really know the LS 16, but I have an LS 25. IMHO it's at the drier end of the ARC spectrum - more neutral SS than romantic tube sound. That seems to polarize opinion. Some love it, others not so much. I also own a few other preamps that bark up the more traditional tube sound tree. I'd be hard pressed to recommend one over the other because they all sound different enough that other factors (system match, room, etc.) become dispositive. At the end of the day, I suspect that it'll come down to system matching and personal taste.