It should work just fine with PC2700 memory -- if you buy PC2700 memory, make sure it is 'solid' (ie brand name).
Buying PC3300 memory at the moment is most likely a waste of money, prices are likely to drop and standards should be more firmly in place before you go with PC3300.
As it is, you are paying more for the PC2700 memory than the motherboard itself
Since PC2700 'pays off' with something like an XP2200 or XP2400, I'd look getting a motherboard likely to support that sort of CPU of course (333/400).