Geoff,
I just searched all over the Deere website. I find it odd that they don't offer a plow themselves. I wonder why.
Obviously there is a market for it if Curtis makes one.
Darrell,
You didn't mention if you currently have any equipment you could get attachments for. I know you may want to get a new machine for this task, but sometimes you may already have a machine that could be adapted. For a 60" wide walk, a skid steer would be nice. The bonus of that, would be the various attachments you could get for it. It could do other things besides clearing the walks. You could mount a pusher box on it, or the bucket for stacking, a PA plow on it, a scraper box to back drag away from doors getting closer, easier than a truck, the possibilities are endless. The cost is the highest too of all the sidewalk machines you could choose from. Then again, it's possible you could use it year round in your business.
You also didn't say where you are, and how much snow you get. This would affect my decision on this. I mean if you get 3 snowfalls a year on average, of 6" or less, as opposed to 14 snowfalls of 3" or so, etc, etc.
I'd definitely want a sidewalk machine with an enclosure and heat for all those walks. A happy machine operator is a productive one!
~Chuck