as alyvn said mate everyone u speak to even experianced builders will tell u different things, eg when i was talking to various reguarding wrc head gaskets one company swore by raceline ones the other used the ones that used 2 be £300 odd back in the day!! then long studding wise from memory karl norris doesnt? but others do reccomend it. mine was already long studded so obviously stuck with that lol.

Also as said if u have got to wear in another set of rings then might aswell have a new set of shells while ur at it!!

Cam wise i'd suggest you get advice from whoever is gonna map it as to what cams to use going by what power u want from it!! Bd14 with standard exhaust isnt a problem thou but it all comes down to how ur going to want it to drive and how ur going to use it ie fast road or track etc etc