Not sure what part of PA. you are in but you want to make sure any Footings / new walls are at least 4 feet into the ground .

Honestly, you need a good partner, contractor or PM on the ground.

A slab-on-ground? 

Boots on the ground is where you will find your deal. 

So start building relationships with them for when your real estate empire really gets off the ground.

I met guy who got an old mobile for free and let the local volunteer fire department burn it to the ground for practice.

Within a few years, your cash flow locally will easily trump what you're getting out of state as well since rents are mostly STATIC in turnkey markets.Unless you can work the grounds out there like a TRUE local, you will be paying a premium every step of the way (acquisition, rehab, PM, etc)...I guess what I'm saying is don't take for granted what you've got going for you in your own backyard.

Here is some back ground of the problem.

Sometimes people get caught up in the dollar signs.Just keep yourself grounded and avoid all the hype that people will try to get you to buy into. 

They had redone the roads, keep the grounds maintained, clean bathrooms, a big meeting room/building for parties, a fishing dock (although it was on dry land at the time due to drought),  even rental spots for RVs were nicer so they pulled an upper end crowd.From what I've seen in my immediate area (and I've researched it), if you have cabins at a trailer park rent pretty decently.