The Lure of Salvage

[pjmuck]

Hello, everyone. I'm new here and I'm hoping to get your advice:

I'm a singer/songwriter who also plays guitar/bass and a little keys. Over 10 years ago I had a crude home recording setup consisting of:

-Amiga 500 with Music X sequencing sofware
-Roland U20 keyboard
-Tascam Portastudio 4 track
-Midiman
In addition, I've got the necessary mikes, cables, amps, etc.

I still have all of this gear with the exception of the Tascam. As primitive as this setup was, it was a lot of fun and taught me how to work with midi, synching, and general home recording. I haven't done home recording in about 10 years though and I'd very much like to get back into it. At present, I have the gear listed above in addition to:

-Imac G3 with 333mhz processor, 6 gig hard drive, 2 USB ports, 96 megs of ram, plus anadditional USB hub with 4 more inputs. This is my main home computer so there's lots of other junk on there.
-Powermac 7500 w 100mhz processor, 1 gig hard drive, PCI slots, 64 megs ram. Currently gathering dust in the closet.

So here's my question(s):

Considering the gear I currently have, what would be the cheapest and best solution for making the leap to a good MAC computer-based audio/midi system? Can I get away with using most of what I have, or do I need to scrap it all and get new gear? I've got about $1000 to spend if necessary. I've got Pro Tools free on my Imac now, but ideally I'd really like to have 24 tracks of recording. It seems that the older Imac has limited ports, however, using only USB. Could the Roland U20 still work as a master keyboard? Can software-based instruments and effects like VST rival hardware based stuff? If so, could the Roland simply input the midi info and use the internal software instruments/effects? This would certainly solve the need for external patch bays or multiple in/out interfaces, though with USB ports only I'm limited with the available combo Midi/Audio interfaces available to me (I only know of the Quatro, MBox, and Edirol). The other option (I think) is the Edirol PC300, which is a keyboard midi controller with a USB connector that comes packaged with Cubase. And speaking of software packages, what are your thoughts on the main ones (Cubase, Performer, Pro Tools).

There's just so much stuff out there that I'm a little overwhelmed, and the more research I do the more my head starts spinning. So if I can work with some or all of what I have and still put together a great setup, I'd prefer to go that route.

Thanks in advance and sorry about the long post!