This is what I do for tomato, and cucumbers, may be more than you want to do.
6' tpost with concrete wire or 4'ft fence with 3"-4" squares.
Drive tpost 6'-8' feet apart, stretch and attach fence 1'-2' off the ground, as the plants grow I weave them through the squares. Very sturdy.
Another trick I have used. Make your cages out of the above fence materials drive tpost or 5/8 rebar in the ground and attach the cages to the tpost/rebar. Very sturdy but uses a lot of fence.
Never found a commercial cage that worked well for tomatoes, they work ok for peppers and eggplant.
