Sorry - this was supposed to be a reply to a post about recording on a computer - stupidly I created a new post - sorry, and I don't know how to delete it :blush:
I think that there are a lot more plugins available for PC than for Mac, including free ones, so that's something to think about as well. It's worth remembering that an audio interface will work on practically any computer. Even Pro Tools, notorious for being picky about hardware compatibility, will probably work on any bog standard computer (i.e. cheap, Pentium 4 and above). However, you would be limited to recording on very few tracks but one way for you to dip your toes into the water might be to get an M Box (version 1) off eBay, and learn about hard disk recording. Also, if you get any piece of Digidesign hardware, you get Pro Tools software with it. I'm using a Pentium D with 4 meg ram, hardly cutting edge, and I can record big sessions - 40 tracks, plugins like BFD 2, Omnisphere, etc, and FX and EQ and it works (and crashes and stalls now and then) but having finite resources makes you make decisions, and that has to be better than constantly being unable to commit to anything!
I bought a dedicated music PC from Red Submarine - it's been great, and a lot cheaper than a Mac - the main thing is that the PC/Mac is a tool to creativity - don't get bogged down in a quest to have a bigger, faster one, etc, etc.
Another tip is to browse user forums - Digidesign User Conference is a good one - look and see what PC and Mac Pro Tool users moan about. Also, search out Mac user forums - suss out what their gripes are.
just my 2 cents