Then go do another one with your friendship intact.  

Friendships, partnerships and mentorships will form by caring not only about what you need but also what they need.

From your experience would it be a good idea to mix past friendships with current business that way, or is it better to look elsewhere for a contractor?

You have to get the services of a quality lawyer, and expect to make some compromises if you want to keep your friendship intact. 

You can do this yourself but you take on the added risk if the deal doesn't pan out or your friendship fails. 

This will ruin the friendship. 

I also networked and made amazing friendship which people I will likely invest with for decades to come.I certainty could have been more aggressive and taken bigger chances, but I did what I felt comfortable with. 

I've created some great business relationships and strong friendships from business and real estate meetups.

GOD willing, this is going to be the beginning of a strong friendship and a very profitable relationship.

Hopefully start a new friendship.