DOing the EFI conversion as we speak. What did all of you do for the fuel regulator. Did you continue to use the stock unit? IF not, what brand did you use? What is the advantage to using an aftermarket?
Use the stock reg if you don't have many engine modifications. AccuFab and BBK are a couple names that come to mind for aftermarket 5.0 regulators. Adjusting the fuel pressure is handy when you need more fuel, but 19lb injectors are totally maxed out at ~300hp. Ideally you have a means of adjusting the pulse width without touching the FP, but that is an advanced topic in iteself.
I used the Holley adjustable unit, but only 'cause it was powder-coated a cool bright red. lol... There is some advantage in being able to adjust your WOT fuel pressure but, as 65ShelbyClone points out, that's an advanced topic. If you're just setting it up, it doesn't cost that much and you may find it useful at some point in the future (also kind of a pain in the neck to access once everything's together)...