Either one if fine. Functionally similar. I think the Meprolight warranty is a little longer.
Either way, look for the kind that have a white ring around the insert -- which allows you to seem them better in daylight.
I've had Meprolight, Trijicon, and PT, and prefer the Meprolight. (The PTs I had failed in less than a year, but were replaced under warranty very quickly. Have several friends who bought PTs and will NOT buy them again.) The colored (red, orange, etc.) PTs are much less bright than the green.