Hey-
I think something to keep in mind is that the American tour operators work very differently than the Canadian ones. If you decide to do an all-inclusive resort the Canadian companies usually book as a package deal with the resort, transfers and airfare as one. Usually, but not always, it is cheaper than booking rooms directly through the resorts and then trying to find airfare. Plus, the tour operators offer a group discount as well as concessions for the bride and groom i.e. free packages per every 20 guests or something. So contacting the resorts directly (with the exception of contacting the wedding planners for dates) may not be all that effective.
However I booked my November 2010 wedding in October 2009. I was able to get quotes for all the resorts I was interested in. So, I think your TA should be able to do the same. While my TA is based in Ontario she specializes in group travel and DW. You can PM me for her contact info if you want to try contacting someone with DW experience.
Good luck!