There are a few older boards that can be recapped, rechipped, modified, and perform very well. I'm not familiar with all the models, but there's one by soundcraft (the 200b I think), the Yamaha PM1000/PM2000, the older A&H boards, and a few others that I can't think of right now (maybe Midas Venice or TAC Scorpion, I'm not sure)
As for currently available stuff, there's the Toft ATB, the TL Audio M1 Tube Tracker, the Manley tube mixer (no eq's), A couple models by Speck (xtramix and another one I can't think of, no preamps) there's a new one just announced by Focusrite (the
Control 2802, mic pres, but no EQs), another one just announced by Harrison (the
950m), and I believe someone is prototyping a mixer that accepts API 500 series modules, but I can't remember who, and I can't find it now.
Personally, I think the problem with sinking $3k into a mixer is that chances are, either the mic preamps or the eq's or the master summing module will disappoint you (until you get up around $10k or so but then you're almost in the neighborhood of
real large format consoles), and aside from that, you're getting 24-32 of the
same pre/eq. I'd go with a combination of an API 500 rack (or an SSL X-Rack if you're sold on that sound - I just got a Mynx and an XR-425), the pres/eq's of your choosing, and a passive summing mixer.