It's got to be wider than your tractor, preferably wide enough to give you some wiggle room in drifts.
As TGReaper alluded to, if you are near the max of your lift, wet snow will over load it. Some days I struggle to raise mine.
I'm happy with my 50" Buhler, once up and back and my lane is clear. It was easy to add hydraulic cylinders for chute and rotation control.
No one was prepared to cut me any deals. Local Deere dealer treated me like customer so he got my business.