Help me decide part 2

So I've got my block at the machine shop getting bored 30 over, and I'm getting ready to put my 408 all together.

Here’s what I have:

A 65 Barracuda that’s about 3000 lbs (without my fat *** in it)
26” tires
3:55 gears
Stock 904 automatic
2000 stall converter
Un-ported stock 360 heads with 2.02 intake and 1.6 exhaust valves
9.0 to1 compression
Scat 4" cast crank
Eagle Rods
Icon 9977 forge pistons
Stock Iron or Edelbrock RPM dual plane intake
Later model cast iron Magnum exhaust Manifolds
A hydraulic roller cam 224/230 @ .050”, 276/282 adv, .503”/.510” lift (1.5:1 rocker), 110 LSA

My Goal:

A decent idle
Good low end response
Power in the 1800-6000rpm range
Max Torque approaching 500 ft-lbs (board curve)
Max HP 400+

I just bought a single Edelbrock RPM head that I got a pretty good deal on. Originally I was just going to use the cast iron heads I have which are in real good shape (they even have bronze valve guides installed). My question is, should I go ahead and stick with the old heads and will that get me to my goal, or should I buy another Eddy, gaskets and head bolts (total cost ~$1500).

If I use the iron heads and sell the Eddy I know I'll save a boat load of money, but is it going enough?