Best way to transfer a home from parent then turn to investment

[Alan Hernandez]

I am asking this for a friend in Kentucky that is now interested in starting in real estate. My default answer was "Talk to an accountant or attorney that specializes in real estate."
That said, his mom moved from Alabama to Kentucky to be near them. Now she realizes it is cold and just wants to uproot and travel for her remaining years. She has a house loosely estimated as 70k with 30k estimated repairs to bring it in line with other comps of ARV $150+. It also appears it could rent for approximately $1000 - $1200. She owns it outright.
The mom is pretty loose with it saying "Just take the house and pay me some money over time." He and I agreed this is a bad idea and he will do a more official purchase agreement that will ultimately be seller financing.
But I thought I would ask for him and for my education if there are any recommendations on tax efficient ways for him to acquire the house since it is in the family. He is not sure yet if he wants to go flip or rental with it. Thanks in advance for input.