Yamaha DTXpress/DTXplorer/DTXtreme

Save up your money and get a decent amp. Like Liberatus pointed out, the way 
to go is a keyboard amp. What happens when you play a drumset through an amp 
is each sound is peaked (short duration) which needs a lot of power. This is 
very hard on an amp. You need to have lot of power or it can sound like you have 
a blown speaker. Especially with the kick drum sound.  I have a Roland 
KC-500. It is 150 watts with a 15" speaker and horn. I consider that a minimum. I 
had a 100 watt Acoustic Guitar Amp with a 12" speaker and that was terrible. It 
sound OK except when you heard the Kick Drum.  I also used for a while a 4X10 
cabinet with a 300 watt Bass Amplifier. That rocked!  But I sold it cause I 
needed the cash. But don't skimp. You will regret it.

Claudio Ortiz