VERY familiar with moorings charters out of the Conch House Marina in Marsh Harbor. They are the BEST outfit in Abacos for charter. It is a GREAT area to charter in with lots of pristine and deserted beaches...a bunch of good harbors and neat settlements on the individual Cays most with moorings, the water is more beautiful than the BVI as is the coral...the land is not as it is flat and dry. Excellent USA style grocery store in Marsh so no need to provision with the charter company.
Best time to go in in the spring. I like March cause you can still snorkel and spear lobster till 4/1...but the weather is great in April and May as well. Weather is very similar to Miami so you can judge comparably.
Get a copy of Dodge Guide to Abaco for your wife for Xmas...it will keep you both busy for a while figuring out what you do not have time to see!!
Amazon.com: The Cruising Guide to Abaco, Bahamas: 2008 (Atlantic & Caribbean Pilots): Steve Dodge: Books