Samng, where about in Campeche. There is some fishing along the coast up from Merida. Also, down in the bottom of the hook, there is a old tarpon camp named El Tarpon Tropical. Up to a couple of years ago, I had a neighbor that would go down and fish for tarpon a couple of weeks at a time. Also, Holbox Island looks nice. I'm hoping to get down there before it is completely developed. It's not that difficult to get to, either.
Vera Cruz is also another place that is underrated but, due to the lack of guides and boats, it can be difficult to fish. Most of this is offshore and lagoon type fishing, tarpon and snook.
If for some reason you want to head south, but can't get to where you were wanting, you are always welcome in Texas. We are entering a great time of year with the speckled trout moving on the flats to spawn, sight fishing for redfish will be kicking into full swing and Texas' Striped Permit (sheepshead) will be some of the bill o-fare you can sample. PLUS, you can drink the water....in most spots.
Where ever you end up going, I hope you have a good trip.
"Fly fishermen are born honest, but they get over it." Ed Zern