I started out as a kid working in trap clubs. My boss owned everthing there was. I became a Trap shooter and hunter. In addition to using my Dad's guns, my first gun purchase was an 870. Then I bought a Ruger MKII, then I bought a Model 700, then my brother was robbed so I bought a Glock 21. You know the term slippery slope; from there I decided I had to have everything,and multiples of each.
On the south end of your gun rack I would put rifles of the .308 persuasions. Can you kill a moose with a .308? Anyone who has a wife that understands why he needs to own Trap guns will also understand why he needs AR's too. Mine does.
All these Trap shooters are naturals for owning tactical shotguns. I would buy some land and set up a 3 gun shoot. Only your shoot would be Trap, Tactical shotguns, and rifle. Bring pistols in later. Hit them where they live, make a competition out of it, and trap shooters will show up. I could just see all these guys trying to out do each other with their tricked out .308's.
If you are going to go into business, your goal has to be to take over the island on any gun purchase $600 and up. Also, all parts and gunsmithng. You need to start letting everyone on the island know you are experts.
Any sporting clays on your island?