Nick, I surprised myself.
I'm a firm believer in partitioning, and at one time I had all my drives on the G4 tower at max allowable partitions. (OS X, OS 9, Linux, Linux boot, swap/scratch/vm, doc, downloads, programs, etc, etc.)
But when I got the G4 Powerbook, I elected not to wipe the 60G HDD and partition. I can't boot OS 9, so that's not an issue and classic is installed along side the OS X system. Fragmentation may be a concern down the road.
My thoughts ran more toward Gary getting to know the system first, to see how it fits his workflow, as is, and using his older machine as a pure OS 9 system for a while.
I believe he does regular backups, so if after a month or two, he feels he needs to partition, it should be a 'piece of cake' to do it.