bump... just wanted to keep this alive... i really need some directions guys! Thanks!
I'm a big fan of "Logic". It comes with all four kinds of drums, Midi loops, 4 to 16 bar recordings of a human playing an acoustic drum kit and single hit samples. I can edit the loops, make my own or add more from a third party. And then it comes with a virtual drum machine too (sliders and knobs to can move with a mouse or asign to a control surface). You can control this real time with any device, a drum pad, keyboard, midi drum pedal or whatever.
But Logic is a huge and complex beast. and you may not something so general purpose if all you want is a a drum loop. The most popular specialized drum software might be toontrack's "EZdrummer" and related add-ons
http://www.toontrack.com/products.asp?item=7But my preference was to buy into the big package and then I can do a "guitar loop" or piano rhythm loops and it all works the exact same way and I don't have 30 software packages to learn.
People here tend to be into classical solo piano music. They don't use drum loops under Chopin. But I got into this whole area because I wanted music to go under my video slide shows. Logic is perfect for this. You can "compose" a hack soundtrack using loops in 30 minutes that keeps exact time to the video.