I would use an experienced broker who can shop around and help you compare best terms on a National basis.

Your father-in-law will want to minimize his tax liability on the capital gain and think about how the sale fits into his estate planning strategy.

Connect with The Hard Money Co, Mach1 Lending, MGM Capital or Plan B Homebuyers. 

I invest in Boise, ID and do quite a few BRRRRs, LTRs and STRs- varying degrees of success depending on how much equity we can force and the type of back end financing we can find, but the tax benefits are great and it's a rapidly growing market and Idaho is probably the most landlord friendly state in the nation. 

They are offering to buy my rental...seems as though they will 3rd party sell it immediately, likely to a fix and flipper. Not sure if they are legit. Their website says they do lots of things in the real estate world...

If you surround yourself with the right people—those who are actually in the trenches doing deals—you’ll pick up the skills, capital, and opportunities naturally.Looking forward to connecting more and building with you, Robert. 

Quote from @Frank Flores: For a rookie with low investment capital, what investment strategy would be best for me at this time?

This seems to be breaking down new construction and is a national average so kind of hard to read into this what it means in general but I would not expect a 665k new construction house to be my target for a rental property. 

I think you would benefit from researching other markets with the capital you have etc.

You are in a great position, and your capital is precious.