The PMS is plug and play with any stock computer, This way if something happens to the stock computer you can just replace it and not lose your tune. http://www.andersonfordmotorsport.com/
Just my opinion if you dont buy some good heads id just stay 302. One without the other is just not optimal. Dont get me wrong, those heads aren't bad but much better is available.
Just to throw in a different option... I am running a 1993 Mustang mass air system on my car that I calibrate with a device called a TwEECer. Up till now, it's been on a mainly stock 302. This coming year I will be installing everything onto a 351. The TwEECer allows me to make adjustments with a laptop so that the car runs right with the smog equipment removed and the larger displacement...but the learning curve is pretty steep, and it is not for everyone. I guess I am a glutton for punishment. Just wanted to throw in a different take on the EFI stuff...