E-Maxx BL suggest diffs and bulkheads?

[RC Fan 4 Life]

Just got a new BL e-maxx and am looking to upgrade the weak points. I'll be adding two 3S LiPo soon.

I'm looking to replace the diffs, bulkheads and the Transmission.

I was thinking the GA diffs and FLM bulks but maybe the FLM front and Rear Hybrid Bulks would be better? I would like to stick with one brand to keep things simple.

And i don't know where to start on the Transmission for the extra power i'll be getting with two 3S LiPo. I think the new BL emaxx only has one speed? as where the older one had two. I've been away for 4yrs so i have lost track.