Yep. the MV100 might be worth checking into for a low cost solution. There's info available in the Oade archives on a drop in replacement chip to replace the SSM2017 that's in the stock unit--really a very easy mod. Will probably help make the MV100 sound much better. As is, I think it is a little thin in the low end, which'll probably help with the mc012s.
I've been tempted to get a used one to dink around with and change out the preamp chips, but there used price hasn't seemed to fall too much even as the V2, MP2, and just about every other pre has. I always see them for $250 used which seems a bit steep. I sold mine years ago for $275 back when used V2s were fetching $950. If you can pick one up for $175 or maybe 200, I'd say go for it.
Otherwise, maybe an AD20 or Dmic-20 (which also uses the SSM2017 and can be upgraded), or for some more loot, a V2. Tapped into someone's octava>V2 at a festival in VA a few years back and it sounded pretty good. I'd stay away from transformers with the octavas, at least line transformer adapters and the mp2, don't know about the psp2.
-Todd