Private Loan Structure Question

[Adam Sieg]

I've searched through the feeds but haven't found a good answer to the question I'm searching.  I'm hoping others with more experience (or opinions) can provide thoughts and feedback. 

I have a family member interested in REI and willing to put forth $50,000 as a private loan. I'm trying to figure out how best to structure for a buy-and-hold property (that's currently my interest and only options right now).

So, if I can utilize $50k as a down payment (20%) on a $250,000 house with a potential cash flow of $800 (Cash on Cash ROI of 20%) would the following terms be acceptable - ie would you do it?

Interest rate: 8%

Loan terms: 20 years

Payment per month: $418.22

Cash on Cash ROI - 10%

The plan is to 1031 exchange in a few years, whereby the principal would either be paid back or would the terms would be discussed and revised for a better cash-flowing property.

If, I have any math errors or oversight please let me know.  Curious to get peoples feedback