I'm still learning, and I've had friends that have built b20v's but they all spent massive amounts on them, i've talked to the builders and they have said that you don't need it for the motor to be reliable and make power. What i'm looking at right now is the following:

B20 block
block gaurd
gsr oil squirters
gsr girdle
rs machine 84.5mm type r b20 pistons
arp rod bolts
arp head studs
decked head b16 head
supertech valve train
s2s2 cams
aebs manifold ported runners n bored 68mm inlets

any POSITIVE advice on machine work would be appreciated, ive been told by builders and tuners that doing a port n polish wouldnt really make much difference in power. Thanks for the advice.