The LLC only holds the raw land and it's completely paid for.

I would push for very low or no money down but having a Realtor that needs to have their fee paid it may still not work.Look up the owner if possible through truepeoplesearch.com and call them up directly.

A DSCR loan is going to require more down, have high fees at closing, a higher interest rate, a pre-payment penalty, and will require you to have cash reserves that you likely don't have at the moment.

(So unless they sell for much more than they paid they will only get a small percent of their down back, especially after selling costs,) but you did say they were getting a discount.

Just remember though unless you have deep pockets you need to at a bare minimum stay cash flow neutral until you get the property running and your debt paid off.  

I was out of cash and he needed to get paid.

@George Blower yes, If any funds go to pay the seller note it will be a contribution first to the Solo K, then paid out to the seller.

Is it best to just throw cash flow at the loan untill the principal is paid off (current cash flow between the two properties after interest and all expenses are paid plus vacancy rate = about $250 left monthly) refinance at renewal to pay it back in full? 

Interest always paid on time, and principal was returned with bonus right on schedule.

I did use Quickbooks, but it was really cumbersome and expense (we paid a bookkeeper to manage it.)