Sorry to say, but I don't think that this Sawtooth, inexpensive as it may first appear, would be a good deal for you. While G4s do have the advantage of altivec, which boosts performance in many OS X applications, 450 MHz is certainly below the minimum system requirements for most of the programs you mentioned. Like you said, that Rage card would also have to be replaced; when you add up total costs for the Sawtooth, new processor and graphics card, you're talkin' over one grand. For that kind of cash, you could get a brand new top of the line 1GHz eMac 80GB HD, superdrive, Panther & iLIfe. (Though the eMac's HD is not 7200rps; only towers come with that. But it probably is not your iBook's HD that is too slow for iLife, but its processor.
System Requirements:
Macintosh computer with a PowerPC G3, G4 or G5 processor
600MHz G3 or faster required for GarageBand
G4 or faster required for GarageBand software instruments
733MHz G4 or faster required for iDVD
256MB of physical RAM )
You might also consider the purchase of a used QuickSilver.
The decision is yours, my friend.
http://www.macsales.com/ http://www.xlr8yourmac.com/