ORIGINAL: MoB KyotE
up the shaft to an alum. one
I'm going to get my upgrade parts and drift until I break my propshaft

Then just upgrade it all in one go
Psycho, I'd have put 3 of your choices much further down the upgrade route than that. I'd do:-
Ball Bearings, CVA shocks and Aluminium/carbon propshaft
Steering kit
Adjustable Arms
Carbon Fibre Upper brace
Sway bars
A decent ESC with either a Team Orion Method R 15x2 OR a Mamba Max 5700 (and buy a new pinion gear to lower the ratio until you learn to cope with the power, and another one for after that when you will inevitably want to do a high speed run

)
And then some decent batteries+ charger.