I always check the AOPA airport information for my alternates. They have info on not just the airport basics, but also fuel prices and (usually) when self-serve is available. Looking at RIU, if self-serve is available, it's not listed.
BTW, I did do a quick sketch of a plan out there. It's about three hours in the air each way -- which is about $900 in rental fees. Worth contemplating, but probably not to be done on the spur of the moment, especially since RIU appears to have tiedown fees. I find it amusing that turkey are possible obstructions.
If I show up at your door, chances are you did something to bring me there.