GULF69
There are several handling agencies at FACT, however I can really recommend The Business Centre. They are more than capable of handling a Gulfstream and they have everything you want and more.
Arriving on an international leg will require you to park on the apron (122.65 for the gate), but the aviation business centre can meet you there and help you through customs, etc. From there the aircraft will be moved to their aprons and it is really quite easy to find.
Catering, fuel etc is all available from them.
Look forward to welcoming you to the cape whenever it is.
By the way the babes are hot, and the beer is cold down here!!!!