My Painter wants half down. What's the best way to cover my self?

[Ray Loveless]

I'm doing a small flip on a house 2 hours away in Utah. A fellow BP member gave me a referral of another flipper in the area. I called him about contractor suggestions and he mentioned that his son does painting and other handy man work.  This is just what I need! He wants half down for the paint work($2100).  He said he accepts Cash and Venmo only(no credit cards). What would be the best way to cover my self here?  I think a lot of people would just pay the money but I would like at lease enough information I can go after him if he walks away with my money. I don't have time in my busy day to drive down there and have him sign something.  I'd prefer to pay venmo but haven't had experience paying a contractor this way. Any suggestions? thanks. -Ray