I would maybe look at your project as stages, rather than the whole picture.
Bring in a contractor to look at your main driveway/ road to the RV pad. And your utilities route. Have him or multiple guys come bid it. Explain where you want to start, and where you want to end, they will be able to look at the grade and tell you what will work and what won't. You'll have options and a expert eye put on it.
They will know the utilities companies, who to get the dump trucks from which quarry, and will make you a road that will make access easy in and out, that will hold up to traffic. Excavator/ dozers ctl and whatever else they have in their toolbox.
Once you get the RV pad and road in, then you've watched the inital work, and maybe you'll have a better eye for what you want to do. Then maybe you can get one machine, and figure the rest out. Dig basements, clear trees. 4 wheeler paths, road to the big house, a path to the pond you're going to build, or the creek.
We do lots of work at different locations, and the people who cut corners on their initial main road/ driveway, end up doing it twice. Need a well? Got to get in a drill rig. Power company has to get line trucks in to bring power. Basement and buildings are going to need concrete and a pump truck. Wood deliveries, and windows and your flooring guy isn't going to want to need 4wd to get to the house. It goes on and on.
I'm all for doing things yourself. But I think building in your main road on slopes, changing grades, with trees to remove, is going to be more than you can get done with one machine. That doesn't mean you can't buy a excavator, and clear the trees for the road guy, but maybe just realize, that some things are better left to the guys that do it everyday, with more equipment.