Need Advice!! What would you do?

[Cameron Young]

Hello everyone! This is my first post but have been reading here for awhile. Love this site. Ok, so here's my situation: 

I have an LLC with two partners (a lifelong friend and my brother), we started our venture last summer with 4 single family homes, owner financed to us, doing great, no complaints. Just closed on our next deal, a 14 unit apartment, so 18 units all together within the first year. We have a nice cushion fund in the bank and we'd like to keep it that way.

During this past year, I have had numerous friends offer me their money to "jump in" with us. I haven't asked for a dime. These friends trust me and believe in me. What I'm needing advice on is how to use their money to benefit both of us? What are some strategies that could make this work? When I see people offering me money, I want to find a way to use it. Right now, we are only focused on buy and hold properties. I would love more apartments but am looking at a couple duplexes as our next purchase. 

Would it be wise to somehow use their money as the down payment on the next property, leaving our own cash in the bank, and if so, what kind of terms would you look for? I view this as an excellent problem to have. Any advice is greatly appreciated.