Before you go out and buy tennis balls and a tennis racquet check to see if any of your players or players parents play tennis. Really you don't need new tennis balls for what you are doing, everyone that plays tennis throws balls away or has tons of old balls clogging their house. As for a racquet you can use a youth size entry level racquet. One of the kids or parents probably have a kid that used to play and gave it up. I'm sure someone has a racquet to donate.
was planning on trying this, but preliminary inquires (not to my team, just friends, our draft is the 21st) is that used tennis balls dissappear really quick, kids use them for all types of games, get used for dogs, cut open and put on things as protection, etc. will try. also gonna try play it again sports, closest one is 45 minutes for me, but will take a trip one weekend coming up I think.