If you are interested in sailfish, you ought to try calling Oregon Inlet Fishing Center and Pirates' Cove to see what boats might be down there.
I used to run my boat down to Isla Mujeres, which is just offshore of Cancun. When I was doing this annually, there was only one Mexican boat that I would have recommended, and it was a 34'er. Can't recall that fellow's name right now. But at that time of year, a bigger boat is definitely a better bet to be able to go sailfishing.
Any good NC boat in Cancun will be fine, and almost all of the boats in Isla Mujeres will pick you up and drop you off in Cancun too, you can see Isla a couple of miles offshore of Cancun.
This time of year, the Mexican's with the one exception, won't make the run to the fish.
JPK