Advice needed on setting up equitable partnership

[Keith Montgomery]

I would like to get some advice on setting up equitable terms of a partnership, which I have never ventured into before. I read through several forums, but could not find exact same scenario which is not surprising given multitude of permutations. Finally, I realize, there is no set standard and a partnership is what we make it. I own a few rental properties solo, so not totally new to the real estate world, with all those disclaimers…

A close family member is allowing my wife and I to invest a considerable amount of money in real estate. They will be hands off from beginning to end: finding property, making offers, oversight, one day selling. My wife and I will carry the conventional loan (75%), family member will contribute the entire down payment (25%) on properties we purchase. Buy and hold strategy. We will hire a property management company if the property is out of state. We will be responsible for all long-term oversight.

Any advice on appropriate division of expenses/profits/appreciation for this partnership? Should we be solely responsible for loan interest? I know if we every sell the property family member would recoup initial cash investment in property. Thank you in advance and please let me know if I missing important information for you to provide an informed opinion.