Need Advice on Financing Multi-Family Property

I'm new to REI but starting out with "buy-hold" strategy specializing in small multi-family properties. I found a combined multi-family property package (3 duplexes) for sale by owner. I'm aware residential loans cover single-family homes up to 4-unit homes, and commercial loans are for 5+ unit homes. My question is, since the owner is selling 3 duplexes (all at the same location), will I need 3 residential loans for each duplex? Can I just get 1 residential loan to cover all 3 properties since they're just 2 units per property? Or, am I required to use a commercial loan for all 3 duplexes (6 units total)? Any advice is greatly appreciated! Thanks, Nhia.