I've had experience with this basic condensor mic. It's not bad. We recorded with Pro-Tools and with Garageband and it came through clearly. (we didn't use the USB one though-you can buy the non-usb version and hook it up to some small M-Audio Fast Track or Mbox and have a decent recording though)-nothing studio like,but enough to get demos and stuff tracked.
http://www.guitarcenter.com/MXL-MXL-...35-i1177542.gc
It's not the fanciest nicest thing like the upper end ones, but then again, it dosn't sound like you have a nice studio with equally nice equipment.
And are you wanting that Auto-Tuned T-Pain style or were you meaning you wanted to stay away from it? Because there is another program that is suppose to be smoother at the transistions of 'auto-tuning' called... Melodyne
Threaded Mode