Alpine and infinity both have good ones!
References :
Crutchfield.com

Try Hifonics, made by http://www.maxxsonics.com they make very good amps for a pretty reasonable price, most used amp @ all the world finals 4 years in a row. check out http://www.sonicelectronix.com they have great prices on just about everything, spl is kinda ok, but we burned them up pretty easy too
References :
http://www.maxxsonics.com
http://www.sonicelectronix.com

hifonics is a good company but its realy a matter of opinion… spl makes good clean mono blocks and i bought a 2200 watt one for 250 so its really up to u …some people like to have a complete kenwood system from cd players to amps and subs…
References :

no doubt. you got a SQ sub, so dont ruin it with a sh*tty quality amp.

normally i’d recomend Boston Acousitcs, or Diamond Audio. but to be honest, woofersect.com has a hell of a deal on this Audison amp.

http://www.woofersetc.com/index.cfm?fuseaction=product.display&Product_ID=4280

imo Audison amps are damn near the best amps you can buy. McIntosh is probably the best, but Audison is right up there with them. hella clean sound, excellent quality. MUCH MUCH better then the Alpine you can get at Best BUy. if i needed a amp, this is exactly what i’d get. hella sell, on a hella amp.

good luck
References :

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References :

Cadence or Zapco would be right up there on my list , also I would recommend using a class A/B instead of a D class if SQ is what you are after.
Go to http://www.imagedynamicsusa.com , go to the forums and ask matt or horsemanwill they should have some good sugg.
good luck.
References :