If you cannot find a 460, the 400X and 400CX mounts for the current 4000 Twenty series also fit the 4500, 4600, and 4700 tractors. Granted new loaders will be more expensive than used, but finding a used 460 with the mounts may be difficult. Good luck.
The newer designed loaders (400X and 400CX) are more capable than the older, 460 model. The curved boom design also gives you a better view that benefits your ability to see the bucket as well.