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. 

I've seen subs (not in privity) claim that performing minor work, say punch out items requested by a new purchaser such as yourself, extends out the time limit. 

Loan Buy Down4.

So they ask to extend at the last minute.

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.