Swaping 781 heads into a 454, what cam/carb/ etc?

I'm finally going to be making a few more changes to this big block and just don't understand what the consequences will be if I do everything I have planned, so I hope that I can get some input before I really screw this up.

Here are the changes to be made:
1-Thorley headers w/dual x-pipe and Dynomax.
2-High-torque mini starter (brand to be determined)
3-VooDoo 60201 cam w/roller rockers (procomp rockers it think).
4-Double Roller timing chain/gears (S.A. Gear or CLOYES).
5-HEI Distributer (not sure of which unit yet...MSD, procomp?)

Now comes the decision part....should I keep the peanut port heads and use a Wieand 8017 intake w/600 cfm Edelbrock carb?

OR should I replace the heads with the rebuilt 781 heads (intake is 2.18 - exhaust is 1.88, CompCams springs #924) that I have; in which case I would use an Edelbrock 7161 intake w/(600cfm or 750cfm)Edelbrock carb.

If I change the heads what should I expect the changes to be for COMPRESSION, HP, MPG, coolant temps, etc???

I don't know which heads I have FOR SURE YET, but I'm 99% positive they are the small peanut heads and the motor is stock, I don't know what the compression ratio is right now, can I find out somehow? The pistons are just stock.

The TH-400 transmission is as "bulletproof" as it can get and is coupled with a gear vendors. The coach is a 1986 28' and tows about 5-7K in trailer (for the last 6yrs). Coach has 75K miles on it and last year all the "extra parts" were removed (a.i.r. pumps; A/C and anything else that got in my way).

Thanks in advance for any advice on these decisions