need some help with selecting cylinder head Mopar 408

Also if you choose to go for RHS cylinder heads, make sure your comp rockers will work with them.

there have been cases of some heads that have an issue with some brands aftermarket roller rockers. (not all heads and not all brands)

http://www.forabodiesonly.com/mopar/showthread.php?t=174593&highlight=RHS+rocker+geometry

These forums have plenty of highly reputable engine builders/machinists who can point you in the right direction in determining this

I personally could only recommend machinists/engine builders I've had work done with inside Australia.