Thanks for the input everyone. The bike is an '08 Cannondale Synapse 7. I'm going to get parts I'll eventually throw on another frameset. So far I have upgraded the seat, seatpost and pedals. The fit is just about right, about 95%, but I may look at a new stem in the near future.

My thinking on doing the wheels and cranks is:
less rotational mass in the wheels = better
and
stiffer cranks = better power xfer = better.