I'm not sure but I think a 1480 has the same size elevator as a 1460? If its bigger its not by much. (1680s have lots bigger elevator.) Have a neighbor with a 1460 with 8 row and you have to set stakes to see him move.
If your yield is going to be much over 150 you'd be happier with a 6 row then you wouldn't have to worry about blowing apart your clean grain elevator. But if you can get a good deal on the 8 row that works too there's nothing wrong with going a little slower.