[sepateous]

hi,
i'm getting ready to purchase an mbox.
i know i also need:
more ram (how much more?)
external firewire hard drive (is 60-80mb enough?)
i'm also considering an rnc compressor or two for tracking.

this is what i have to work with so far:
imac dv se
os9.0.4 (i have os9.2.1-should i install that?)
400mhz
128mb ram

sony spressa usb cd burner (how can i get this to work since the mbox and keyboard take up my 2 usb ports?)

i have plenty of mics.

sorry for all the stupid questions, but searching through here has been extremely helpful.
i'm a singer/songwriter and probably won't use that many tracks.
(acoustic guitar/vocal - maybe percussion/mandolin/dobro etc.)
i just want the bare minimum to get started smoothly.
i appreciate all you help so far.
thanks!