I don't know what power your subs will take, but I currently have the Kenwood 729S hooked up to a 10" JL Audio 10W3 and it thumps just fine. The guys at Myer-Emco recommended the 10W3 sub, and it sounds great in my car, not underpowered at all... btw: the 729S amp hits 300 RMS, 600 peak, which I think is fine for most under $200 subs. Correct me if I'm wrong, but it at least works with my 10W3 nicely.
HU: Pioneer 880PRS
Amp: Alpine V-Power 800w Mono amp
Sub: JL Audio 10W3 x 2
Speakers: Stock components