Pismo as audio input for QS

I got a Quicksilver G4 733MHz to use as my recording machine. It doesn't have an audio input. I'm going to pick up a PCI card eventually, but until i get $100 to get a decent one, is there any way i can use my Pismo G3 as an audio input, using the FireWire or even USB? Almost like an iMic?

Also, does anybody know of any decent audio cards cheaper than the M-Audio Audiophile 2496? I know they have a $100 one, but I'd like to get RCA and MIDI.

Thanks!