We have a situation very close to yours… a large gravel driveway.
I would definately get a large two-stage. We have one in an area that get 18" of snow in a night, and we have a 10 HP Troy-bilt that is a few years old. You will want at least 10 HP. And BTW, the Toro Power Max snow blowers are just your standard 2-stage.
Most blowers of this size offer a 110V electric start. We have this on our Troy-bilt, and it is a godsend when it is 0 degrees and you haven’t started the thing in several weeks.
When we bought ours several years back, we asked the local small engine mechanic (who services a lot of snow blowers) what he would get, and he recommended three different brands: Troy-bilt, Ariens, and John Deere. Not sure how things have changed since then, but we have never had a bit of problem with the Troy-bilt in almost 5 years of service.
Some tips I would offer:
-After you get it, get chains for the tires
-Most large blowers will have all the features you need, the electric start sometimes being optional. They will all be self propelled.
-Since you are blowing over gravel, raise the adjustable skids up to their highest setting so you don’t suck up too much gravel.
-Get one with drift cutters, they really help for cutting through a lot of snow.
-Get one with heated handle grips. This makes things much more enjoyable when you are not freezing your ass off.
-Get a couple extra sheer pins for the main auger. These pins are meant to break if you hit something you shouldn’t, so you don’t damage the drivetrain, and are eays to replace. They are really cheap and you will break one every so often.