For comparison, a Navy Federal FCU personal loan will be in the 15s%

The lot is paid off and deeded to our LLC, but lender will not do conventional loan to LLC for the remaining financing so we'd need to take out a loan in our personal names. 

I've done this with my properties because I'm well known in my small town and don't want people to know what I own.LEGAL PROTECTION: By placing your assets in an LLC, you are legally separating them from your personal assets.

My recommendation would be to engage an investment property focused realtor (not a general residential realtor) and let that person guide you through the process from pre-qualification to market/property valuation and selection. 

I'm not a professional Tax person.

(Either with the roofing company, a heloc, or a personal loan.)Either way you will probably be way ahead on interest saved unless you have a sub 6% interest rate.

A relative who does long-distance real estate investing told me that I have to sign the final loan document and the transfer of ownership document in person.

I would recommend going to some local real estate networking events and asking around in person who people like to work with for title.

@Enrique Toledo  If the seller is firm at 10% down, you can always get a personal loan for that 10%. 

I’m the last person who should complain about grammar, but these are yellow flags, at best.