You might go with the old reliable double hump 68cc heads, If you want to stay with a cast iron head. The come std. with 1.94 intake valves, rework the exhaust to 1.60 smooth out the bowls and port match the intake. If it were me I would run a Performer RPM intake........stay away from the tri-power set up, more looks and nostalgia than performance.

Good Luck with your project
Alan