I'd be more inclined to go with a conventional design and maybe give up those extra 5" of space. Here is the install I did on our unit... 5000 BTU and only 350 Watts, can't beat those numbers!
https://www.youtube.com/watch?v=Duua4EVesos
This combo of a 900W Yamaha inverter generator and the Fridgidaire 5000 BTU wall unit will get you 9 hours of cooling for only 0.6 gallons of gas. I doubt any kickstarter unit will be beating that anytime soon. I even worked with a Chinese rooftop AC company to get a 5000 BTU unit designed and manufactured, and for $700/unit they still were at a 500W draw. I'll stick with a tried and tested $120 wall unit.....
Frigidaire 5000BTU A/C Unit ON SALE @ $119:
http://amzn.to/2Aln0kp
Yamaha 1000W Inverter Generator ON SALE @ $790:
http://amzn.to/2y5ka1s
