I'd say, for your budget, if it is pretty set, the Stampede 4x4.  That will be the most versatile vehicle for where you are planning to run.

SCTs and STs are great trucks, but they are really most at home in a track environment.  Get too far away from a well groomed surface, and the smaller wheels and low ground clearance will become a huge disadvantage.

For multi terrain bashing and romping around, the Stampede 4x4 is a great truck.

On the flip side, if you plan to stick to the track and the trails, a 4x4 Short Course Truck would be a blast in those areas.

I'd love to tell you to stick it out and wait for a Thunder Tiger MT4, it would be the best choice of any of them.  But it won't be back on the market until September, and it is a little outside your budget.