The Deere's have a loader models with self leveling buckets. They've been around for quite a while.Its not a valve skill deal. The curl cylinders are on pivots that maintain bucket (i.e. fork) level positions while you lift. See the 562 and 563 loaders. We use one for feeding the cows so you don't spill a bucket load. You don't need special skills, valves or training to get the job done. Perfect for forks.
Do your homework. Plus, the extra pivot links would be easy to make for changing a hinged bucket to a self leveling one.