HG parts

[west_side_supra]

ok so i know im going with the HKS metal HG. but what one?

ARP studs are better but harder to put in but head bolts are easier just cant torque them down as much <right?

timing belt most people replace cause its already taken apart and might as well but is not necessary?

turbo , exhaust , intake manifold. new gaskets also? or should i be good?

head and block should be machined to a Rough average of 25 or better?
is there anything else i forgot to mention that would be needed in order to fix a BHG.

what exactly does the machine shop need to do and will i have to take the block out of the car?

thanks guys.