Edelbrock makes fuel rails to go with their EFI intake for the 390, I'm sure they would adapt. You can find them on Summit. I know some people also make their own, you can google more info on that.

You can download the software that the TwEECer uses for free and play with it on your computer, may find it easier than you think. I recommend Binary Editor for this, check out eecanalyzer.net, they also have outstanding tech support.