For bashing with your Evader I'd recommend something like a Hitec HS625 or JR 126MG. Both can be had for around $30-40. They have plenty of torque for steering your stadium truck, reasonable speed (.15-.17) and metal gear durability for bashing.

I'd run the servo saver as loose as you can without affecting the steering response. You should be able to force the v-shaped wedge in the saver to move with significant finger pressure but it should not be able to slide completely up and over the crown of the piece it fits into. With the better metal gear servos you can get away with running it tighter