[dohc82]

I don't have the mechanical skills for doing an engine swap on my own, so it would seem a lot more cost efficent to just keep the 5m.

20psi... yeah, thats wishful, lol... think I could get to 15 for about 4k? The body is in good shape and the transmission is fairly new (about 30k miles)

If you dont have the mechanical skills to do an engine swap then you probably dont have the skills to build a 15psi system from scratch. It would be more complex than a straight engine swap. Especially considering how many resources there are to help with the 7m swap.
If you want quick power cheap then look into the Holley nitrous kit for our cars.

-Wil