Well if you're aiming at performance and not bling, and are looking to keep it affordable, I'd switch to:
Integrated aerobars/stem/basebar
RENN rear disk
The normal P2K frame (Though how much does the P3 cost??)
Ultegra 10 components though frankly I'd grab an Ultegra 9 group and get the cheapest brakes you can find

The disk wheel and the integrated bar system is going to make a hell of a lot bigger difference then the weight difference between the two frames and the DA and Ultegra componentry (especially the rear disk)