If you want some serious power to pump your sub, run a MMATS D class amp (D300hc, D200hc, or D100hc). I have a d300hc and i stand by them completely. you are going to come out of pocket for it, but if you search around you can find them for reasonable prices. The main difference between the amps are the ohm loads that they run at (d300hc = 1200watts @ 2ohm, d200hc= 1200watts @1ohm, d100hc= 1200watts @.5ohm)
I'd have to lean towards W0's being the best bang for the buck. Throw them in a ported box tuned to about 30hz. Push em' with about 600w to all three ( 200w each) and you will be cooking. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif