This should make the decision slightly easier...
The two trucks you listed are the same. Completely and utterly identical chassis, suspension & drivetrain. The ONLY differences between the two are the paint jobs on the shell and the box. The truck was a joint venture between the two compaines (Thunder Tiger and Associated) and they each released their own version.
I own a Thunder Tiger MT-A4 with the original .21 engine and it is a great truck. Tough, fast, easy to work on. Couldn't be more pleased with it.
Try reading this thread...
http://www.rcuniverse.com/forum/m_4050020/tm.htm