Getting Started, choosing software and audio interface Options

[JPSpecial]

I've been reading the forum for several days now and, while there is a wealth of information, I'm still uncertain what kind of setup would suit my needs. I have a 17" G4 imac with 768 mb ram running OS 10.2.8.

I'd like to record my acoustic songs: guitar, voice, maybe some bass, perhaps some drum loops. I would have gone with Garageband but the fact that it won't allow me to record a guitar part and voice at the same time, assigning each to different tracks, was the real killer. So, I've read a lot about software: Logic, ProTools, Tracktion, and others. I've also read about audio interfaces but have become thoroughly confused with all the options, usb and firewire. I will be miking my voice and the acoustic guitar (2 mics). I especially want to avoid latency. Sounds like a major frustration. I also have no experience in digital recording and would like to keep the process pretty simple while still achieving results that sound good. I'm sure any option will be a major step up from my Fostex cassette four tracker!

Thanks in advance for your input.

JPSpecial