What sort of distributor?

I am looking for maximum streetable horsepower in my 545 build and the next item on the list is a dizzy. I have a Crane Hi-6TR (timing retard) ignition with an LX-92 coil, am I better off going with a remanufactured duraspark or an MSD billet such as the 8580, or something else again? I have seen in the Mad Porters ad that his durasparks have worked on engines up to 700 hp, I'm not sure how much I'll end up with, I suppose it depends on the wisdom of the cam grinder as to how much Hp they consider streetable when I get the custom flat tappet done. I'll be bolting on a set of "out of the box" P51's and there will be a 100-300hp zex nitrous kit hooked up as well. (not when on the street of course!) Any input appreciated.