receiver packs are always nice the one i got came with a wall charger and an extra connector for and aftermarket charger. I can show you witch one it was if you want the same.
I personally like my 2 speed because i dont go on long straights doing high speed runs. i just do a homade track down the street so i dont even have enough time to get outta first. i guess it depends on your surrounding if you should get a 3 speed or not.
I personally liked the aluminum exhaust pipe from HPI... really nice sound over the plastic. and cheap if you can find em on ebay.
Also i havent had any issues with the diff's so far and that truck is mainly used for jumps and hard landings. just over all tough driving.
i would say if you have bigbore single shocks.. work on upgading those.. for mine it started sagging in the rear after the break in. or maye buy some wide axle conversion kit give it a wider stance for more control.