I'd buy a Cessna 206 and base it at KRAP (have to love that identifier). Buy a truck or van and leave it at Edgemont and either work a deal with one of the Operators to use their pilots (flying it Part 91) or look locally for a pilot for your own 206. With the number of trips you plan on doing, do it yourself. You'll save a fortune - you could even afford to buy your own helicopter for that matter!