Most seller finance deals are shorter term (in my experience at least), generally 5 years.  

If you are interested in shorter term fixed rates that could save you money, you still want to stick with conventional loans and just pick a 5 or 7 year ARM. 

Which again, would mean you're that much closer to having a paid off rental house that pays you around $15k a year or more, after taxes, insurance, and capex for the rest of your life.Now, all of that said, if short(er) term cash flow is a priority for you and you don't mind exponentially extending the time by which your loan will be paid off on that property by several years or by decades - then by all means, do that.

With your credit, specifically Fannie/Freddie.For your commercial, portfolio, hard money, generally speaking, these are going to be higher rate, shorter term, typically balloon in style, so that you have to redo the mortgage every so often.

The BRRRR strategy is normally used on shorter turn around times (6 - 12 months) to get out of the higher interest rates of the finance methods I mentioned.I have a couple of questions.What is the current mortgage payment for your SFR?  

For shorter-term financing, IE "Fix & Flip", the fees/rates are higher and the preapproval is typically a little less formal. 

Offer shorter/flexible leases in exchange for slightly higher rent &/or no placement fees (with the bonus that most CEOs looking to buy a new home have too much to lose to go trashing the place).

On the other hand it could be a shorter term with a larger payment.

I know commercial are shorter with higher rates and the occasional massive balloon payment.  

Or even put the money into a shorter term syndication, puts your money to work while you wait for that next MF