My advice is to find better advice than on this forum - all you will get here are answers in the form of questions that make assumptions on your wealth, knowledge of building codes, business experience and experience regarding RV's/camping in general. You will be told how expensive it is to put in a septic site, and all the horrors of permitting something like that. You will get several responses asking how far from a major freeway it will be and endless debate on which is better - closer to the interstate for those who want a quick overnight, and those who want peace and quiet. Then, someone will come along and tell you that buying or building a CG is not going to be the cash cow you expect it to be, and that it will not be a vacation.
Good luck in your endeavors - more CG choices are always welcome.