The bearings that come with the car are "shielded" meaning that they don't have rubber contact seals. Bearing kits, like that from Fast Eddy, typically feature sealed bearings. Sealed is better for outdoor use.
RPM suspension arms for 2WD ECX vehicles (an excellent upgrade):
Rear swing arms:
RPM70462
Front swing arms:
RPM70582
I DO NOT recommend the RPM front spindle carrier as the shoulder screws work they way out of the softer plastic. Instead buy Hot Racing's ECT2106 "aluminum steering blocks." You can then secure the shoulder screws with a bit of thread locker glue and never have another issue.
I really like ECX's own aluminum shocks. They're actually quite nice for the money and are a direct fit. I've experimented with Traxxas Big Bore shocks and did not like their performance. I recommend replacing the shaft seals with "x-ring" type o-rings. The x-rings have two ridges that effectively double the number of sealing surfaces without increasing drag. There are many brands (Associated, Yokomo, Kyosho, Traxxas, Losi) but I use Kyosho's "P3 grooved o-rings."
Front shocks ECX1095
Rear shocks ECX 1096
I can't really tell from the photos but did you install RPM's "Servo Saver Eliminator" steering bellcrank?
For wheels and tires? I recommend just sticking with ECX brand stuff. I once tried Associated's T4/T5 truck wheels but their offset was too much and caused all sorts of problems-- I had to install wider hexes AND 2-3 mm of shims and still the rim rubbed on the steering rod end during hard/fast turns.
The ECX Circuit wheels are pretty cool looking, too:
ECX43004
As for tires? What surface will you be driving on? There are tons and tons of options out there.
