buying amplifier help..

Hello. I have two xploids -12in 1100w i think, running from a two channel 110w radioshack brand amp. I know this isnt much to be pushing, lol, a whole 55w to each, and taht is why i was wondering where i should get a good cheap amp around 300w-400w two channel or four channel crossover online or in store? I always see like offbrand amps, but never know if i should buy them, so if anyone acn help me it would be greatly appreciated. Oh, the amps i saw cheap so far are at www.etronics.com if you wanna take a look there. Thanks for all the help!