Anyway, I'm confused on the operating plan.

The idea is to create cashlow and wealth through equity and appreciation so the plan we can build few units , sell them and split profit 50/50, while I am the boots on the ground overseeing the process of building from start to finish, meanwhile the partner brings 100% of funding. 

My sister lives in the area and I can't imagine anyone planning a vacation to the Ozark Lakes over Branson.

I think it is more of a 20 year development plan, so cash flow now and let your investments grow naturally over time. 

Perform comprehensive due diligence, such as financial analysis, title searches, and inspections; also, go over lease agreements with renters to make sure they are aware of their rights and responsibilities.If all goes according to plan during the due diligence phase, close on the property, complete the financing, and get ready for the ownership transfer.

Secondly, who cares what the ownership splits are if the gain can't be realized because the values are propped up/can't meet projections, the sponsor cannot execute on the business plan or the fee structure severely eats into the distributable cash when the realization event actually occurs.

What kind of down payment and renovation costs should I plan for?

It'll take real work from you and him to be able to execute this plan.

Two rentals are enough hassle for me and I don't plan to buy more unless it's a deal that's impossible to pass up.

When it closes not only will I be able to pay the HM loan off but I would also plan to pay the personal loan off and still walk away with a decent profit.