Welcome to the forum...
Because you've already admitted you get more than a foot of snow several times a year, I wouldn't get anything less than an 8hp, 2 stage! And if it was me, I'd say geta 9 hp. You may be limited because of your door, I know, but don't skimp on horsepower, you'll need it!
You've got a decent size driveway...not to mention the slope. And I would bet from your pics, you're going to get some serious "drifts". I'd get drift cutters on it also. Electric start is nice to have, and usually most new machines have that in the price range you'll be looking at. A headlight is nice to have also for those dark mornings or late night snow storms.... you know what I mean!
You'll hear all sorts of brand names on this board: Ariens, Toro, Honda...to mention a few. They all make good quality machines that, with reasonable care , will last a long, long time. Change the oil, keep them maintained, and they'll take care of you!...
I say buy from a dealer if possible, because he'll back you up with his service and you'll know that it was assembled correctly! As far as other stuff goes: locking differentials, hand warmers...don't know because I've never had them on my machines, so what you don't have, i guess you don't miss!
You're probably looking at between $1000- 1300. for what you need. I know it's a lot of money but... you'll never regret it the money you spend on a quality machine. I , for one, still haven't forgotten last Winter!
Hope this helps...