Take over Payments/Wrap around mortgage

[Richard Pierre]

I have a take over payments/wrap around mortgage deal in the works. I've never done one before. I know this much:

1. Get him to sign an authorization form allowing me to get all his mortgage details directly from the lender.

2. Comps to determine if there's enough spread between how much he owes, and the house value (he said he owes about 100k, the house is valued at 130k). Mortgage plus PTI=$850 month. Currently getting $975 from a HUD tenant.

3. Get a contract highlighting this a takeover of 'existing' financing, and give myself a 90 days grace period before the first payment.

4. Have a real estate attorney prepare all closing document

5. Close

6. Market property for a tenant-buyer. Probable terms: 10-15k down/120k. Cash out Finance in 2 years. 

Can someone help me and make sure I don't blow this deal?