The good news is those heads are cheap. The bad news that they won't be so cheap by the time you get them working correct. But they sure are cheap!

Seriously if you are really interested in those heads then the best thing to do is to contact Porter Racing Heads and get a quote for what those heads will be finished and ready to bolt on an engine. With rocker arms, valves, springs, seals, machine work and assembly you're probably looking at something in the $4000 range. That will tell you the true price of those heads.