........Bite it !!!
Jeff, i presently own 40.5', previously i had a 28' hunter and installed an 8000 btu self-contained reverse cycle A/C under the V-berth with two discharge registers at the bulkhead between the V-berth/salon. it was great, kept the boat cool in summer and warm in winter with reverse cycle.(better choice than heat coils) also had an electronic programable thermostat,(with memory battery). mine also was only powered by shore power. overall, you can't beat it, it's the way to go. Yep,...it is more expensive & more work, but once it's done, you will be happier!!! Or you can spend a little less with a "pain-the-butt" portable, haul it back & forth or up & down & cuss when it rains/leaks....not to mention nites that are not quite warm enough to haul out the portable, set it up, plug it in, (...extention cord??) also, how about a condensation line??. in the end, available space is going to govern your decision. if you have room for the built-in, do it!!! remember though, you'll also need room for the portable, above deck or below deck,...or haul it back to you truck!! i don't know, but if you ask me, i'd rather just lower the thermostat. good luck, Jim