Re: Promariner 2500 or Xantrex Freedom 2000?
The REAL issue you should consider is this: with a combined unit, if one side goes belly up, so does the other. Maine Sail has long been a proponent of separate units and there is great validity to that point of view. Especially given your situation, where you do not "need" AC power when not at a dock.
That said, when I researched this for our new-to-us 1986 boat in 1998, I did all my homework, research and cost estimates. I chose to go with a Freedom 15 and a Link 2000. The Freedom "forced" me to consider how to wire my charging systems (shorepower AND alternator) since the Freedom only had one output, just like the alternator. Back then most folks had moved to separate house and reserve banks and used two output shorepower charging systems, so they didn't worry too much about the single alternator output 'cuz they'd go home and plug in. We liked being out on the hook. That's how I "discovered" the Yandina combiner, which remains operative on our boat.
That said: If I were you, I'd buy separate units.
Stu Jackson, C34, 1986, M25 engine, Rocna 10 (22#)