The AKG D190 is a nice neutral sounding mic, good for instruments as well as vocals. Fairly low output so when you change from plugging direct into your computer's sound card to going through an external preamp or mixer you should get a lot less background hiss.

A Mackie 1202VLZ would suit you quite well. 4 really clean mic inputs, stereo output, bass, mid and treble controls. Even if you don't need all the other mixer facilities, the Mackie is good value for money just for the mic preamps which are disproportionately good for such a low-budget device. Also it's tiny for a twelve-input mixer (rotary main faders help).

Anahata