RV head vs. PB head

[Spyda]

Are there any other differences other than the valve sizes? Does anyone know the intake and exhaust valve sizes on each head. I think the PB head is 40/33.

The reason i ask is
1: I've always wanted to know but could never find out.
2: If the valve size is the only difference, would it be cheaper to port the RV head to 40/35 and reco it rather than do the same to a PB head.

Also, can anyone give me a rough price on increasing the valve size from 33mm to 35mm and what else is involved.

I'm keen on a 2l bottom end with a ported PB head, duel down pipe and cam running digifart.

P.S. I know about 16v's and vr6's so no need to tell me again lol