If your running at a track that's where you'll get all your answers...
I run two classes at a local outdoor track here on Okinawa...
The Tamiya class solves most of those issues as it restricted to tires, body, motor must be Tamiya. Battery is Nimh stick 3700 or less.
The 23t class is limited to 23T brushed motor, 3700 nimh or less.
Most guys here run Sorex tires (28r-40r depending on temp), yellow team bomber inserts and we are allowed to use tire sauce. I use Flap tire juice.
Bodies are open just as long as they are touring car style, like Mazda 6, Dodge or even the R9 or LTC.
Check with your club rules on lipo limits, pretty sure it's gonna be a hard case.
As for a charger, I like my ICE from duratrax but you need a power supply.
I also have three AC6 chargers from hobbyparts.com a good deal for 55 each AC/DC and seem to do a good job.
Servo is your choice, I run digital futaba's 3151's I think...
RC and Beer Brewer
the only way to DUI!