Your criteria and the November time frame does not lend itself well to any of the better Central American diving.
The Bay Islands can be predictably wet, and anything North of there will be wetter if not more exposed to tropical storms. The South side of the Bay Islands would likely be do-able, but there really isn't much on the entire island that fits into the category of "luxury"... one way or the other, anywhere you go might be thought of as "roughing-it".
Your 5 Night criteria throws a serious monkey wrench into your travel criteria for avoiding "difficult/time-sapping travel connections". Ease of travel = Saturday to Saturday for most Caribbean Central American destinations out of Atlanta.
Your criteria of "We don't enjoy roughing it on holiday, so pleasant accommodations and easy access to diving is mandatory" is vague enough that any reply suggestion might be acceptable.
In November, for my money, if you were hooked on this general region, I would look at Bonaire or Curacao. Still a fair (4/10) quality of diving, if you want to pay for it- there are lovely resorts, no sand flies, and fairly easy air access from Atlanta (even on a 5 day mission).
Have you considered cruise ship diving?
