Hi chrisrap1, glad to see you joined us here at TV.
I have been using the same 5 gallon setup for my tomatoes and I have found a perfect system for those buckets. The grids I use fit perfectly on the buckets and I zip tie them to the holes in the hole the handles were in to hold them just in case they fall over in the wind. That has not occured yet and I am on my 2nd season using the grids.
My first season I used plain old cheap tomato cages but they just didn't want to stay in the bucket as well as I would have liked, so I bit my lip and decided to pay the money for the grids. I am happy I did because they will last for many years and easy to put on the bucket and just as easy to take off. Here is a photo of my buckets, the photo was taken with the EB as the focal point but you can see my buckets behind it.
I got the grids at Gardners Supply Company and here is my review I wrote about them there.
"I connected two of the grids with each short side (19") shaped in a half circle and then attached them to my 5 gallon buckets by sliding them down onto the buckets leaving me with 34" of height. They are sturdy and I believe will hold a patio tomato without any problems and certainly much better than the wire cone style purchased at the local garden store. I might drill a hole in two sides of the bucket to attach the grids with zip ties to be sure it doesn't come off in case the bucket falls over. Otherwise, I think if you are not in windy areas that step is probably not necessary."
There are 4 grids per order and I used 2 per bucket for 34" of height. You can always stack them higher and use all 4 for a much taller indeterminate, but I am not sure it would be wide enough to support the really long branches, you would get with the indetermninate tomatoes.
Here is the link,
http://www.gardeners.com/Flexible-Ga...tableGardening