You might want to post this over on the Tomato Forum for better answers as I don't have much personal experience with growing tomatoes. But as you've found out, those little three ring cages are not good for indeterminate tomatoes. Indeterminate varieties easily grow over 6 feet tall. You can try to add stakes around the plants and tie the stems to them.

Rodney

Here is a link that might be useful: Tomato Forum

I have grown Mountain Pride and love them.It has been a good producer and has not had any problems.Good for humid south.