If your not looking for anything special, just goto your local shop and pick up something like an Alpine 2 Channel mono amp. And, if you didnt want too much, should've find an auction for only one sub. 1 10" is plenty.
Alpine is good stuff for amps, IMO. So are Xtant and JL, but i doubt you wanna pay those pricetags. All else fails, goto Best Buy and get their weekly special. It'll suit your needs from the sounds of things.