Ari Fleisher seems to be able to polish a turd, but that's politics. For your mic question, If you've got two C3000's, I'd keep one and liquidate the other, and then with $600-$700 in hand, head down to your local pro audio shop to audition some mics and pre's, putting the emphasis on a mic purchase, but either choosing a pre to go with it in the near future, or maybe even getting both. I agrre that the Meek box's are a good direction to look for the pre, especially for metal. I have one, and it's a little edgy. For a warmer tone, maybe think about one of the affordable tube pre's by ART, PreSonus, or DBX. For a killer, agressive tube pre that's supprisingly highly regarded, the Peavey VMP-2 is the ticket, though it would eat up your budget. Focusrite has a new voice strip called the Trak Master that has a discreet pre, an optical compressor, an EQ, a tube saturation emulator, and optional A/D conversion, for $379 street. I'll be evaluating one in a couple of days, but have high hopes for this unit.
Mic wise, I've heard nothing but rave reviews from the users of the Studio Projects stuff, and also the Rode mics. I just ordered a Rode tube NTK myself for $499. I expect this would be a huge improvement over the C-3000.
Ok, gotta go. Good luck, RD