How would you structure this partnership?

[David Morgan]

Friend A has found a motivated seller of a small apartment building and negotiates a price and an outrageously good owner financing arrangement. But as the closing date approaches, he sees that he's not going to have the money to close, make improvements or have a rainy day fund. 

Friend B has the money to make it happen.

They decide to form a multi-member LLC. Friend A will manage the property with help from Friend B. Friend B will provide 100% of the funding for the downpayment, closing costs, and initial improvements.

Exit plan is 1031 to a bigger building in a few years.

Does 50/50 between Friend A and B seem fair, and should Friend B invest the needed capital in the LLC or loan it to the LLC? How would you structure the deal between the two friends?