Hi Jim,
All three are good. I'd start looking at the one with the most recent design upgrade, if that is possible to find out.
I'd much rather see a nice cushion on the capacity side so that rules out any 45 amp models. If you do plan on a fourth panel I'd look in the 80 amp and up. That, I think, eliminates MorningStar.
While I do have a display that does volts and amps output to the battery I hardly ever look at it. An led would be nearly as useful.
RS232 interfaces are technology of the distant past.
