Need a bit more information:
On your cam what is the duration @050, Comp Cams P/N would help too.
Is this mostly a street driven car? Track car?
Holly's Carb selection tool:
I would try to match the RPM range of your heads to your cam to your choice of headers and intake. If you do that you will make the most power across the rpm range. Mismatching those parts will cost a lot of potential power.
Your cam's RPM Range is probably 2000 -6000 (hard to tell without more numbers but based on in/ex lift #s you gave)
Intake ranges you mentioned (from Edelbrock's site):
Performer Intake: Idle - 5500
Performer Air Gap: Idle - 5500
Performer RPM: 1500- 6500
Performer RPM Air Gap: 1500-6500
I would expect one would pick up a few extra HP/TQ from the denser Fuel/mixture with an Air Gap but you will want to check to make sure you have the hood clearance to fit that manifold. I would probably go with a Performer RPM Air Gap based on your cam choice ( Hard to tell without flow numbers from your heads, your cam could be too radical for your heads or vice versa)
A good article on choosing your exhaust system:
If you want it to sound mean I would go with a straight through high flow muffler like Magnaflow rather than mismatching engine parts (too radical of a cam) to get the sound you want.