Re: drum machine advice......
forget hardware drum machines- use soft synths...these days they have nothing to do with midi programming (not like it was hard to figure out anyway)..you will get *much* better sounds...check out Steinberg Groove Agent 2, Stylus RMX, Fruity Loops, or BFD.
Hardware drum machines still measure samples stored in megabytes; usually 8-16mb for *all* of the samples.
Some softsynth drums have libraries that span several DVDs, 30 or more gigs. If you want awesome sounds with realistic phrasing, invest in the software side of drumming.