JMO - stroking the 318 is fine, but more money than a 360 or 340. Understanding you have one already, maybe that's the way to go. On heads - aluminum is the way to go, and there's nothing wrong with Edelbrock or Indy product. But - you have to understand all aftermarket heads suffer from mass production defiuciencies and should be checked and corrected by a qualified shop. LA RPMs would be a good choice for your 390". You need the correct head haskets for them, but they are Felpro Performance. Cometic is not needed, and indeed if you want to run Cometic, you will need to have the heads surfaced because as delivered the surface finish is boarderline too rough for any Multi-Layered-Steel type gaskets.
On Bob George - if you want a crate type engine - he's your guy. If you are looking for a budget Mopar stroker - you will probably suffer from problems after you've got it in hand. BG Racing will not do you wrong.