rb25det buildup help

[240sxrb25]

i have an rb swap in my 240sx and currently have a greddy fmic, garrett t60-1 turbo, top mount manifold, q45 throttle body, new wastegate, and bov. im still going to get the greddy plenum, injectors, some sort of fuel management.
also, at what opint would i need to change the head gastek and switch to studs?

all the products im going to be installing later on are good for about 500hp...they say, does anyone have this amount of power, and is it on race gas, or pump?

a friend of mine suggested that i set a goal power to achieve on pump gas(93 octane).



if anyone has any suggestions for me before i get the rest of my stuff, i would really appreciate the help.

thanks a lot.