soon to be a first time SD user - partition question

[southside]

so, I partitioned the 500 GB Lacie D2 Quadra HD (using FW800) into two pieces - one 80 GIG partition for SDing the 80 GIG drive in the Powerbook G4, and the rest I was going to use for stuff that I would offload from my notebook - things like combining my ITUNEs library from the Powerbook and the one on our old Dell PC (running XP)...

but just read on the BLOG that you need to separate SD backups from Leopard TimeMachine backups... OK, can do that with the two partitions... but if I want both of them (in the future - not right now... still running Panther, but am planning on the LEOPARD upgrade) - will I need the 80 GIG partition for the bootable SD image backup, another large chunk for TIMEmachine to do its thing (maybe 150 Gigs or so) - from what I heard TimeMachine files will build and build and build until it uses up a certain amount of disk space, and than old stuff is aged off?... and the rest has to be another partition - for extra stuff like my combined ITUNEs collection?

is that correct about needing 3 partitions in the future if I want to use SD, TimeMachine, and also have space for extra stuff? glad I went with a 500 Gig drive... probably shoulda went with the 1TB drive... never enough, huh?

thanks!!,
southside
Live From Bangkok, Thailand