Current environment to build on St John

Hello, I am actively looking to purchase a lot on St John and will eventually start the long process to build a place. I am looking at something around 1500 sq ft and 3 beds/2 bath. I plan to act as my own GC and have done this in the past on a remote cabin project so I do have some experience. I am also pretty handy and can do a lot of work myself but I am curious if local contractors are typically fine with someone being their own GC and only bidding out very specific work scope. Also, what is the availability of common material like framing lumber, windows, doors, and general building material on the island to where i can go load up a truck? I totally see this being a 4-5 year adventure once I start the work but I really need to have the ability to perform alot of my own work? Is that common or accepted on the island with permitting?