SFR: Mortgage or Commercial Loan?

[Grayson Warren]

My wife and I are planning to (hopefully) close on a property next month in the OKC area. We have 20K set aside for a down payment. We have spoken with a lender who has tried to educate us on the pros/cons of both acquiring a traditional mortgage versus a commercial loan. The lender has told us both will require 20% down; however, the commercial loan gives us an option of folding in a renovation loan. With the commercial loan, the lender also mentioned that after 5 years, the loan would be renewed but would adjust to the interest rates at that time.

We want to start with a "win." Something that will have decent cash flow and that isn't necessarily too risky, though we understand there is inherent risk in any investment. 

What are your thoughts? Should we go the route of personal mortgage at a 4% interest rate (probably finding a turnkey property), or commercial bank loan (with the rehab loan) at 5.5% interest? 

Additionally, if we did a traditional mortgage, would putting this first investment property on our credit hurt our chances of getting a car loan or personal home loan down the road?