If you don't want to deal with tape loops and volume mismatches just dump the Perreaux and buy an Adcom GFA-750. It is one of the better stereo preamps around bar none, and offers a dedicated HT processor loop to seemlessly integrate with your Sunfire. I think you can get one for $1200 to $1300(less whatever you get for your Perreaux) as they seem to be discounting now. McCormack's new RLD-1 also seems promising if you want to stick with solid state but don't like the Adcom for whatever reason. Someone else mentioned most of the tube alternatives, although I'll throw in Rogue as another option.
As for the pre/pro option, with so many balls still up in the air with the new formats I would not sink a lot of money into a new pre/pro. You'd have to spend a lot more to get a piece that rivals better 2-channel preamps and you have the potential risk of future incompatibility even if they say it's upgradeable(we've all heard that one before). It's just too early to jump in to a pre/pro in my opinion, especially when you can get state-of-the-art performance from the Adcom for so little while milking your excellent Sunfire unit for all it's worth until the dust settles on the new stuff. Best of luck.
Tim
As for the pre/pro option, with so many balls still up in the air with the new formats I would not sink a lot of money into a new pre/pro. You'd have to spend a lot more to get a piece that rivals better 2-channel preamps and you have the potential risk of future incompatibility even if they say it's upgradeable(we've all heard that one before). It's just too early to jump in to a pre/pro in my opinion, especially when you can get state-of-the-art performance from the Adcom for so little while milking your excellent Sunfire unit for all it's worth until the dust settles on the new stuff. Best of luck.
Tim