Get tuning parts.....ball diffs / one way coming out from xray,
there is a 300 motor mount out you can find at unitedrc.com....along w/ tuned 300 motors.....and of course a brushless setup by castle creations called mamba that should be out sometime this week also available at unitedrc.
6 cell stick pack Kan cells...or I've been testing some cells that united will market as basher Kans that are formitable against the Kans performance wise that should be a bit cheaper than the Kans.
(just a note: both Blind and UnitedRC are reliable sources for the Kan cells I know them both to be good people and professional)
consider also 2.5deg rear toe in arms.
aside frome the usual spare hubs, wheels and tires. I run BL so I glue mine (wheels to hubs)