Hey Satayo I suggest go brushless with your setup im running a Mamba max with a medusa 36-50-3300 and couldnt be happyier tons of power im running it off of 14 cells.
I wouldnt go to much power in the e-savage or your asking for drivetrain issues. With the setup im running I have a problem keeping the stub axels from breaking I have even upgraded them to tmaxx ones (just need to do a brearing swap).
you could be all setup for less than $250 and have longer running times vs upgrading your brushed motors