How would you structure this multi-house deal

[Kathy Moser]

I have the opportunity to purchase 3 houses in an off market deal.  They will only sell them as a group and they've offered seller financing.  

All 3 houses need work, including septics, which will run $35,000 - $45,000 per house, plus at least $10,000 more work per house.  So at least $175,000 in improvements, which would have to be cash out of pocket.  Bank financing is not an option for a variety of reasons.  I don't have enough cash to do the 15% down payment, all the repairs and have a 3-6 month reserve.  

Here's the offer I want to make:

I'll purchase house #1 for cash and do all the upgrades, refi in a year and use that to buy House #2, and do it one more time to buy house #3.  

In the two year period I will also find and screen tenants and act as property manager (they don't want to be landlords) in return for 10 - 15% of the rents to go into a fund to go towards the next house.

I want to create a deal where they have confidence I am going to buy all 3 and I am not over extended.  

Has anyone done a deal like this?

Thoughts?  Thanks!