I bought a set of 42" forks locally. Rated for 2200 lbs. They were much cheaper than anything else I could find. I think I paid $350 for them. For the most part, I have just moved pallets with it, and it works well for that. I did use it to hoist my tiller off my trailer that I had purchased. My forks can be positioned by moving them from one groove to the next. This seems to be a common design. Well, when hoisting my tiller, the forks want to tilt towards one another because the chains squeeze the forks together since the forks can wobble on their mounting spot. (I had the chain wrapped around both forks.) So, I sort of wished I had forks that mounted and slid along a bar. I know better now, but otherwise, I am content with the forks.
Cut a 2x6 a couple inches wider than the static gap of your forks, cut a "U" notch in each end deep enough that it fits over the inside lip of each fork and stays in place. Wrap your chain around both forks and lift away. The compression strength of a 2x6 should be more than adequate to match the lifting capacity of the compact or small utility tractors. If you're lifting all the time, it might be worth it to rig up something similar out of metal, but for the occasional trailer offload cutting up a scrap 2x6 is a heck of a lot cheaper than buying a production lifting bar assembly. My 2 cents.