Air Conditioner Recommendations

I would stick with a Coleman with a soft start kit. WHY? Well in a good way Colemams suck.. most if not all the others blow. By that I mean the Coleman/Air-Excel sucks air in through the condenser coil so if you are parked under the tree in cottonwood season you get a nice blanket of wood-cotton all over the condeser making it not work so well. And there's other types of "Crud" that build up as well.

now Remove 4 screw/bolts lift the cover off. peal the condenser clean replace over and 4 bolts job done.. (Take about as long to do as it would you to type it out)

Most others. closer to a dozen screws
Then after you remove the cover still more screws or other fasteners
Remove the inner cover over the condenser. not always and easy job
In my case I had to remove the fan (Big hands)
Then I could clean the beast.
And reassemble. and reseal

That took a lot longer to type.. but the job takes longer still.

Personally I'd go for a heat pump unit, being able to use a bit of electricity to keep from running the propane heater would be great. I can't justify it with a new rig, but if I had to replace mine I'd definitely drop the extra coin.

I can run a Briskair 13.5 with a 2200 but it's working pretty hard. I like using two. It's quieter.

Verify the BTUH rating of the old unit.
If you were happy with that, stay with the same size,,,,, or,
Since you were able to run it off the 2000 watt genny , explore IF you could go one size larger.
If the old unit was an 8k btuh, would an 11k btuh be better? And would the 2200 watt genny carry it.