camshaft choose mopar 408

hello I'm looking to replace the camshaft in my 408 and and do some work on the cylinder heads.

This is in the engine

probe 408 Flat Top -5.5cc - SRS Piston 10.5:1
scat 4" cast, crankshaft
scat I connecting rods
mopar purple cam P4120231 right now
COMP Cams Pro Magnum rockers
edelbrock rpm airgap intake
holley 750 db
converter stall 2500-2800 rpm

the cylinder heads that I shall use is 4027596 G heads.
they will be ported and I will put in the 2.02 valves in them
how much cfm will I need to have in these heads ? so they will go well on my 408.

how about this cam?
http://www.summitracing.com/parts/cca-sk20-225-4

help me guys :)