I really like what Cro did with his cells/packs, nice set-up and easy to build.
Headway 38120P are rated 1500 w/kg....
1000x0.33kg = 330kg x 1500w = 495000w / 746 = 663 Hp x 0.8 (motor and drive train efficiency) = 530 Hp
Is it enought for you?
I ordered my headway cells direct from headway (see p.3) : http://www.diyelectriccar.com/forums/showthread.php/smart-fortwo-ev-high-power-version-51472.html