I dont think I have ever seen 60" drywall. Only 48" and 54"
I as well have never seen 5' drywall... but I do see 4'6" readily available
Guess it depends on where you build. The last house I built, they used all 4 ft, just did two seams for 9 ft. Drywall sub supplied the boards. House before that, I had to stock the sheetrock for the piercers to put up, and I could get 5 and 4, so used that for the 9 ft and 5x5 for the 10 ft. House before that, was doing a lot of commercial work at the same time, diverted one of my big subs over to my house and they used 5 ft for the 10 ft's. He was doing a lot of big work in Las Vegas and vicinity; the rock was stocked directly off a truck from the factory, you had to have a large open hole in the side of the building to let them use a truck crane to put the rock in in full bunks, they had guys pull it right off the bunks and stock it to the rooms, and then pulled the excess back out and back on the truck.
Come to think of it, the rock was all 5/8", not 1/2, on the previous jobs. That might have changed the width availability. Latest house was conventional construction, used 1/2 on the walls and 5/8" on the ceilings.
It's also possible that I remember wrong, and we used 54" sheets.
Point of my post was; figure out what rock width you're going to use, and then frame to that to avoid an extra seam or extra cutting of the boards.