Single Mortgages vs Portfolio Refinance

[Gordon Way]

Hi BPers! My fiance and I just closed on our 10th property (13 units total) in the San Antonio area. He has 4 mortgages and I have 5 mortgages in our own name (we aren't married, yet!). I'm trying to understand how to keep growing the business. We have used conventional 20 and 25% down, seller financing and cash purchase for the properties. We are attempting our first BRRRR method now on a property we did seller financing on. We want to do a HELOC or cash out refi on a property we purchased with cash and use those funds for the rehab portion of the BRRRR. Which is better for this situation a HELOC on an investment property that is wholly owned or a cash-out refi?

Also, how do REIs get 6-20+ loans on properties? Do they have individual mortgages on each property or a portfolio/combined loan on several properties? We started an LLC and want to start using that to get lending; what's the best type for that?

I know, lots of questions but any advice is greatly appreciated! Thanks in advance and happy investing!