The guy taking a sledge hammer to his climateright is definitely not encouraging, but the specs are right.
Here’s the same, 1400 BTU air conditioner (linked above) for dog houses for $299:
This AC is a lot smaller and lighter than the climateright, and it uses significantly less power. The design seems simpler (doesn’t heat and has no wireless remote), which could be a plus. This pet-discount-store ad claims that the AC cools up to 90 cu. ft. The ad at the other site says 40 cu. ft. (with provisos about insulation). Even 90 cu. ft. is less than the volume of the camper, but these estimates presumably assume a poorly insulated space.
1400 BTU sounds about right for the camper. A typical 5000 BTU window unit claims to cool a 150 sq. ft. room or around 1200 cu. ft. The camper is closer to 150 cu. ft.