Size Snowblower?...?

I live in upstate ny in the adirondack region where snowfall amounts can average around 90 inches per year. I just bought a house and need to purchase a snowblower. My driveway is around 15ft wide by 40ft long, and i will need to clear a path to my shed to store the unit, which is about 50ft away from the driveway. I have narrowed it down to an ariens brand, i just need to know the size i need. It appears my choices are the 10hp 27'' cut, or the 8hp 24'' cut. I need some advise, the only other difference btwn the two that seems significant is the fact that the 10hp machine has a headlight and the 8hp does not. Thanks for the help