most important is a good, smooth floor.. We had an old Massey 155 (I think) spreader that perpetually broke the chains.. after unloading it once by hand, we gave up on that idea and flipped it with the crawler loader.. problem with that one was the sprockets were worn and would hang onto the chain as it went around.. don't know what the names of all the chains are, but it was the typical old style chain that used to be found on binders, combines, etc.. you slid the links in together from the side after flexing the chain backwards.
Now we have an old IH spreader, I think you'd call it a T bar chain.. never broke it yet