I really couldn't tell you. My gut is saying to go electric, as it is less likely to go out on you since just about every replacement mechanical pump available is re manufactured and I had four of them go out on me last year.
I have everything on my car to do an electric pump conversion, all I need to do is hook up the hoses. The only reason I have not done so, is I like the originality of the mechanical pump, and I have not yet found an adjustable fuel pressure regulator which will let me go down to 3.5 PSI, and still have a return valve on it.
Converting to electric does require some electrical knowledge, as you have to wire up a relay and the safety switch to operate when the car is running, and not when the ignition is off.