Turbo head build

I have a stock slant six and am planing to turbo it and and going to do some minor head work when i pull the head. Arp studs and porting is a for sure. i do not want to spend the $700 to get bigger valses, should i get stock style replacement valves and backface them. Is it worth it to put in 340 valve springs with the stock cam. I live by organ cams and could get my cam regroud too for around $80 but do i have to get diffrent rockers, cam bearings, ect... (my core cam has some very minor rust on it). My budget is ~600 (not including porting which i will do myself)