Got a deal on a house$150-170kRealtor gave estimate for listing at $199kArv is $285-$315kTrying to figure out how to swing it Scenario : guy I know will front the cash to me to buy it for a cash deal but short term loan basically. 

Construction loans are different than mortgages. 

Loan Buy Down4.

What loan would suit the purchaseIn my early 30s, I often wished my parents had told me to buy a house at 18.

I'm assuming you would need to seek a whole new loan?  

Using private money to pay off the deed then looking into equity loans to rehab and purchase other properties.

Additionally, you'll need to locate a property with either a vacant unit or a shorter lease that could be canceled, allowing you to occupy a unit as your primary residence, as required by the terms of your low down payment loan.

I also found a bank that would finance that low cost of property as a regular 30 year loan so payments on debt is way low obvious $100 - $120 per unit.

Lennar Mortgage which now offers DSCR loans.

When you go to refinance into a long term loan your personal credit score will 100% matter.