We use this type of rig to set them, however we do not concrete them in. Ours are all 4x8 (6 feet inside height) with the floor 10' off the ground. We use 2 T posts on each 4x4 post. Drive them into the ground about half way, much deeper than you do with a fence. We use good solid chain to wrap around the wooden post and the 2 T posts and use a bolt to make it tight. We have never had one blow over.
If we ever want to move the stand we use remove chain and use the lift arms on the tractor to pull T posts out...
