Either unit fits a 14"X14" cutout. The 15K unit will help a little, but that is really too much for one AC. To run two at the same time would require either 50A service or an additional 30A service. I added a second 30A service to my trailer using a breakout box attached to the 50A outlet at the pedestal. It's not hard to do but does require some electrical knowledge.
2013 F250 XLT
I now have a Keystone Outback, but I try to help when I can.
Bitter Gun Owner