I can pear with one fork if I am spearing bales from my 30 year old baler. At times I have trouble getting a spear in the bales from the new baler. They are hardcore and much more dense.
I made my last hay spear. I wielded a frame, bought a 3,000 lb. capacity spear on line, placed a flat bar at an angle at the top, cut out the two bottom pieces and had a spear.
I wielded a quick attach mount on the back of a box blade. It works well. I can still use the three point hitch and pull it from the front.
You can buy a quick attach adapter that allows you to hook up to any 3 point hitch implement. That may be the cheapest rout to go. You could use the spear you have.
The hard part about using the bucket mount you mentioned is visibility. The bucket blocks the view.