Better Bang for the Buck: Strut Tower Brace
Less Trade offs: Kmember Brace
You will reduce the flex in the strut towers a lot when you get a good brace up there. The kmember brace will reduce flex in the kmember but i believe that there are some other items that should be done with the kmember bracing to make it truely effective. If you are going to tinker with the motor then i believe that you will more than likely need to remove your tower brace - which is why i believe it has the trade off.
Walz