We had two 16K BTU Marine
Airrr Vector Compact units originally, still working at 17 years but getting a bit loud -- and recently replaced with Dometic Turbos. Latter bring some improvements -- quieter compressor
, stronger air flow, slightly improved programming interface, better condensate pan, better mounting -- but I don't have long-term experience with them yet.
Not sure about meeting your dimension or power requirements, but you'd be able to look that up...