Drum Machines

[steelcmg]

So my cousin and a few guys are into playing death metal and are having a hard time finding someone to play drums for them. So they where thinking about getting a drum machine. He asked me to see if I could find out some info about them but I know nothing about them. So for any of you music buffs out there what should I be looking for that can handle playing double bass type beats realllllllllllly fast or can all drum machines handle things like this. Links would be really helpful.