Can't you use the compressor built in to your mixing board?
I think I'm going to snag the
Behringer XENYX X2222USB
http://www.amazon.com/dp/B0036ECH0S/...=IIS5AXON6HX8M
It has "8 studio-grade compressors with super-easy "one-knob" functionality and control LED for professional vocal and instrumental sound"
This ought to work out pretty good... I hope...