Purchasing a home for my retiring mother

[Derek Bugg]

Hey everybody! First time posting. Thanks in advance. 

My mother recently retired and is renting. I have been divorced for two years. My ex-wife was awarded the house (with my VA mortgage at a rate so good it won't be refinanced in her name only) and that mortgage is good standing. I have enough VA entitlement left to purchase another home. I want to buy my mother a house and have her pay "rent." My first thought was to use my VA entitlement, until I ran into occupancy rules. (I love my mom, but I will not be moving in with her.) The idea is to ease her worry of future increases in her current rent situation by letting her pay what she can afford toward this new house and I would cover the rest. Since I won't be living in the home, I know I can't get the best rate. If I am the only borrower, which mortgage is my best option? Does the divorce decree showing that my ex is responsible for payments help with my rate? (I've read that mortgage contracts trump divorce decrees and the bank would hold me liable regardless of what the divorce decree says.) I have good credit, debt-income ratio, and could come up with 10% down if needed, 5% preferred. Is it a better option to just co-sign with my Mom, since she will be occupying? Would we get a better rate? (She would not qualify on her own.) If so, would I be co-signer or her?

I know that's a lot of questions.  Thanks for your time.