Almost right. The 6500 does have a 3.3 V regulator, yes, but it only supplies enough juice to power the 603e CPU. Any more load, and it becomes marginal. I'd suggest that if you want to run L2 cache, an AV system, TV tuner, and PCI cards, you really do need a 6360 PSU.
I suppose you could also roll your own 3.3 V supply, but most people aren't that dedicated.
For more information, just search the web for Takky conversions to Color Classics.
Peace,
Drew