What Will Work With My System?, I'm shopping and I need advice! Options

[Roneon]

I want to set up a home studio and I'm not sure which software and sound card to buy. I have a G4 Quicksilver 733mh with 384 mb of ram. It's running OS X 10.1.5 right now and it seems that I will have to upgrade to either Jaguar or Panther. Will Mackie, MOTU, EMagic, CU Base or anything else work on my system? Basically I will only be recording vocals, acoustic and the occasional electric (one at a time). I know I need to get an extra hard drive too but I'm not sure what kind or speed I need.
Any suggestion will be appreciate!

[Roneon]

Thanks for your input Rickenbaker , I am seriously thinking of getting the Spike package (Traction and XD-2 Interface}. I downloaded the demo of Traction and I like the one window world. I have a copy of Micro Logic AV 4.0 and I do not like having floating windows hovering above what I want to see. It also can 'freeze' tracks to free up the cpu.
The XD-2 interface seems like just what I need too!
Though....Reason looks pretty cool but out of my range for now. Maybe some royalty income could fix that.
I think this site rocks! My brother has a recording studio (he uses a PC running Cakewalk though0 so he could not offer much advice for Mac's and suggested for me to find a Mac only forum. The depth of knowledge of the members is incredible!
Ron