AsphaltFlyer,
All of the above is really good advice depending on what you want to do. But from my experience I would suggest a box stock class with the RWD ready sets only, and not do the EVO chassis at this point assuming your goal is close competitive racing with a group that would attract the most racers to build the club. I would get whatever RWD kits you can to start with and add bodies you like later. For rules keep it simple and require box stock radios and mostly box stock cars. You said you already have a track and timer so a transponder is a must for each. You will only need RCP type tires to start with. Options that we allow for box stock class are, Bearings (most RWD's already have them), T-Plate (because the stock will break), Springs (stock ones are super stiff), and Headlights (because they are cool looking and some RWD kits come with them). The most fun and competitive racing is had when all the cars are the exact same radio and motor.

Where are you located?