You could easily make a simple boom pole like this.
If your bucket has bucket hooks, then weld a 2 in receiver to the inside bottom of the bucket. It doesn't affect anything by being there. Cut an 8 ft or whatever length 2 x 2 x 1/4 in wall, and drill a 5/8 in hole in the boom pole to lock it in place at the bucket end. Then weld a 2 in receiver on the lifting end of the boom. Weld two chain hooks to the top of the 2 in receiver. To use the boom, install the boom pole, and attach a chain to each chain hook. Should be tight as possible. You can plug anything in the end of the receiver to aid you in what you are doing, from using a grab hook, a D ring, or whatever will work in a 2 in receiver. Cheap and downright simple. Easy to store also.
If you want to stiffen the boom up some, weld a tension rod on the top of the boom, with about a 4 in rise in the middle.