The Crescendo/PCI G4 700 or 800 megahertz are processors made by Sonnet for legacy Macs like our 9600. It gives you all the benefits of more speed and the ability to run Jaguar on our old machines. It's a bit tricky but if you go to
HERE, you can read all about how it is done.
I had 10.1.5 on my straight 9600/350 but with 1.5 G of RAM and it ran really well. When I upgraded with the processor and new video card I ran in to a SCSI termination issue which I haven't yet taken the time to resolve so I am back to running 9.1 but not unhappily. Things are snappier and I run just about everything I could imagine needing.The other night I had 13 programs going , including Photoshop, Image Ready, Go-Live, Explorer, Fetch, BB-Edit, etc.
You can find a price comparison for the 700 version
HERE. If you click on the "Technical specification" on the right side of the window you will get a popup that tells you more about the processor. Or you can go to Sonnet's website to read more. The only difference between them is a slight bump in speed with the 800 and an additional $90 more.
RAM is the most important thing for your machine. It is dirt cheap these days compared to what I paid when I first started buying chips for the 9600. This is a page with some prices. You need the 128 FWP or EDO. Our machines can take 12 of them for a total of 1.5G.
RAM pricesIf you are not going to run X, then interleaving is OK. Actually I had mine interleaved and it ran fine anyway.
I also put in a new 32 MB video card. But if you aren't doing a lot of high intensity graphics work or playing games, the Twin Turbo that came with the machine is OK. One note, if you do get one of the G4's from Sonnet, then you MUST get a different video card cause the Twin Turbo is incompatible with the Sonnet G4s. I found that out after a week of hell.
BTW, I also have USB and Firewire cards and run a combo USB/Firewire external hard drive which would be good for your music storage.
If you have any more questions feel free to ask.