Sequential circuits samplers

Hello, a special thank-you for anyone that can help me out even the 
smallest. I'm having a hard time grasping the loop editing, so I 
thought using Sound Designer would save me alot of time, and be easier. 
I don't have a Mac, so I'm looking into buying one. First off though, 
can I just buy and old Apple Mac and use that? Like the ones from say 
1984-on or does it have to be a special one...if anybody could tell me 
exactly what Macs I could use, I'd greatly appreciate it. Also what 
other equipment would I need to buy to transfer my samples to and from 
the Mac? I read there was a Mac-to-MIDI interface, is this true? Sorry, 
I'm kinda new to the game, and need all the info I can get. So if 
anyone has any info on the Sound Designer, please I'd love to hear 
something back from you. I do really appreciate everyone's time and 
such, again thanks and have a good one...-L.J.-