Stereo sub amp recommendations

Hi all.

Just looking for some advice or recommendations for adding subs to a stereo system for music listening (not home theatre.)

I have a pair of Acoustic Energy AE1s which are currently running full range, and a pair of polk audio passive 10" 'coffee table' subs which I was running off a Yamaha receiver with a cheap and cheerful lpf set at about 90Hz.

This system integrated nicely and the Yammy at full volume provided just enough power to suggest bass, ie, you didn't notice the subs were there, until you turned them off. Pretty much the way I like it.

I'd like to liven things up a bit, and I'm prepared to spend a bit of money on some more serious amplification, but I'd like to keep the budget to $500 or less.

Things I've looked at so far have been the Dayton SA230 and SA100, and the Bash 300. I am not specifically against using plate amps, at a pinch I could mount them intheir own box, but I'd really like to have the controls at the front. I'd like to keep the mid/his running full range, and band pass the subs, I'll still need to do a bit of gain matching to accomodate different programme level etc, so the more control the better.

Can anyone recommend any amps, eiether 2 channel discrete, or mono, which might suit the application? Something with a low pass option would be ideal. I have no predjudice one way or the other for class D or class AB/H, Just dont want to spend too much on them.

Cheers!