Here is a quick look at what Home Depot in the US has – and looks like Moiseh is correct that it is the 30amp that is RV specific. When you get into 30amp and 50amp plugs and outlets there are quite a few different possible configurations of where the blades and slots are. You must make sure you get the exact correct one to fit your equipment. These are just some examples – and other parts may be required depending on which stuff you buy. Searching will turn up more. But where in Mexico I do not know. Maybe someone can bring a half truckload down?
For use in recreational vehicles
30 Amp 125-Volt 2-Pole Angle Travel Trailer Plug
Leviton Model # R50-00830-00T
Internet # 202077649
Store SKU # 495344
$11.98
30 Amp Flush-Mount Power Single Outlet - Black
Leviton Model # R50-07313-000
Internet # 202066668
Store SKU # 250467
$7.98 /each
50 Amp 125/250-Volt NEMA 14-50R Surface Mount Power Outlet - Black
Model # 3854CC6
Internet # 100576531
Store SKU # 449129
$12.98 /each