milling 360 heads

hi Kim my 360 bottom end is all built now,its at a different shop than the heads,different story there.i now have my 340 915 202 j heads being rebuilt.Thankssss for all the help om milling my heads guys,me thinks I will them as is.I soon will need that intake KIM if you still have it.I have a question on head gaskets if anyone wants to address it.I like the blue felpro ones whats the mim thickness I could use with out any fitment problims.I know the head builder likes the steel ones.Any thoughts.