2bed 1bath SFR rental evaluation

[Jordon Milford]

I bought a duplex, 2/2 each side 7 yeara ago (FHA) lived in it for about two years then bought my 3/2 residence. Planning to purchase a small property for grandparents to downsize in and rent. Property will become a rental when the time comes. Need help on evaluating for a rental 2 bedroom, 1 bath 900 sqft Purchase price: 65,000 Down: 20% (13,000) Rent: 625-650/mo Considering HELOC loan on one of my properties to hold onto down cash, or should I use cash for down? Thanks