Brushless e-maxx - new setup questions

[ozdave]

Hi guys, great forum, very helpful and it has provided me with just about everything i need to place my order for an upgrade to brushless :)

Ok so I have an e-maxx with with a few upgrades, rpm shock towers, a-arms, and skid plates. MIP drivetrain. 3.3 diffs. Pro-line steering kit. Traxxas Big bore shocks. ACNCM bulks. Pro-line Velocity 6 wheels (standard size) with Pro-line masher tyres. Not a particularly light truck fully loaded with 14 cells.

I am planning on going brushless and would like to hit 40mph. After reading lots the top of my list is BK warrior 9920 controller and Wanderer 8xl motor with a UBEC.

I'm will ony be typically running 12 - 14 cells but would lke to have a play and maybe run 16 cells, all NiMh (GP, IB) I bash the truck around a bit and like to do jumps so am not going to go lipo

So my questions are....
Is there another motor I should consider with these goals in mind?
Do I need the UBEC with this setup? Will it make that much difference?
How about a fan? just for the ESC? I'd like to keep it all running cool and prefer safe than sorry.
I realise I will also need to make some gearing changes. Will I be be able to make the changes I want without changing the slipper setup?

What else is a pretty sure thing to go in the first few runs?
diffs? should i just change the cups now given how fast i want to go and the way i use the truck? or shim them? or both?
Steel idlers?
Will the standard transmission hold up ok? I realise first gear will be useless.

Last but not least is there anything i have missed that I need to consider to make this thing a nitro beater :)