If I had to build around the u89s, I"d be looking V3.
I say that because i'm not a huge LD fan for concert taping. and if I was to use them, i'd want the preamp to be clean, and QUICK.
well, Ed's already got a clean, quick, transparent pre-amp, the V2. While I think the V3 is great (I love mine, especially at 24 bit), I don't know if its what i would recommend here. honestly, the V3, the Mini-Me, and the 722 all have very nice A/D converters, and while you will hear a difference between the units, its not going to be a
major change to the sound. You say yourself that you love the sound of your rig, and while I understand the urge to change things up, I'd say stick with what you've got. The MiniMe A/D has a bit more "punch" (for lack of a better word) than the V3's A/D. So if you're looking to keep some of that, I'd say V2 > 722 would be the way to go. The V3's A/D is a bit more "laid back", which I find to be very smooth and natural sounding. The 722's A/D puts a little more "oomph" into the low end, similar to the Mini-Me (but not quite as much, IMO).
I think you should check out a comp between the V3 straight up and the V3 > 722 (which is basically identical to the V2 > 722), it's here:
http://taperssection.com/index.php/topic,81297.0.htmlit's an older comp, but the files are still being hosted so check it out.