Westendorf makes an attachment called the rear-ender. you want to get the high lift attachment as well so you can dump the bucket into a pickup. It runs about 5k (2014) for the complete package.
I picked up one of these a few weeks ago. It's made for a cat 2 connection so I need to modify it to fit my cat 1 3pt. I was looking for a 3pt bale spear but figured this would work for bales and other things.