I have a very similiar set up except I use three 12" woofers in one enclosure. I use an Adcom GFA-565 with some mods done to it. From the factory it is rated at 300@8ohms and 600@4ohms I have no clue what it actually produces but it is loud as I can stand and I am fairly young.... You should be able to find one used in your price range, the only problem is you may have to buy two of them since they are monoblocks and not many people are willing to split them up. That said I have two of them and use one and have a spare handy, heheheh. Also thick (fewer thick strands opposed to the other way around) copper wire is an absolute must. Which ever way you end up going I use an amazing sub woofer cable that you should try, the company that makes it offers an in home trial so you have nothing to lose and lots of bass to gain. So when you are ready email me and I will give you there number and then we can start a thread about subwoofer cables, well maybe not.....Cheers! Tim