Best Solution for 12 Cell Racing??

Hi Everyone :)

Being new to the forums I have looked for what I am about to ask, but I haven't found enough information.

Down here in West Aust we race E-Maxx's on 1/10th electric tracks with a maximum of 12 Cells (within our rules). What I am trying to find out is what would be the best solutions for racing on hard packed clay with only 12 cells?

Before anyone answers - A couple of the guys run C50-Maxx's and one of the fellas runs a 8L. Now, our trucks are around 5-6Kg (11 - 13.2 Pounds, mine is 11) Looking at the wieght of the truck I would be inclinded to look at a 9L?

Gearing! - I run kipsters, what pinion and spur would be a good solution for a 9L?

Hope you guys can help, I am looking to upgrade my HV-Maxx due to it thermalling (I have it geared mildly, I drive it damn hard tho! lol) Thanks fellas! :D

BB