Associated makes great RTRs. I have an B4RS RTR. 5 years old in a few weeks here. Mine was before they made brushless version. Heavily modded now, almost nothing is stock. The Mamba Brushless that is in there is insane.
The T4 is a very good choice as far a Stadium Trucks go. I'd recommend that one. You can get others (Rustler VXL, E-FireStorm) but they are more pricey, $300+. Whereas the T4.1 Bushless RTR is $250.
As for being brushless, if you find one you like that isn't brushless, it's not like you can always just buy a brushless combo after
The stock brushless are fine, but Im very glad I saved up for a Mamba.