I've seen the SW-* sidewalk plows mounted with snowblowers driven by an auxilliary engine that hangs off the back like this one:
The one pictured may be for sale here:
http://www.militaryconvoy.com/1bombardierweb.htm
This would give you a large snow moving capacity in a very small footprint. Pretty slick. A blower would not be difficult to fab for a SW-* or similar carrier, especially if you had access to a plasma cutting table to cut the ribbons and various parts of the blower fan. The other key pieces are the aux. engine, variable displacement piston pump (as shown), heavy duty right angle gearbox to apportion power between the ribbon and the fan, and various hoses, valves, filters plus a hyd. reservoir. I bet you could build one for less than $1500 if you scrounged on eBay. I built my 84" blower for under $1000, not including my time of course.
Whatever carrier you mounted it on will want to be able to travel very slow at times. Hydrostatic drive is the preferred transmission but other similarly low-geared mechanical transmission would do.
I saw a " Snowcat" type about 15 years ago that was a single/two seat machine with a snow blower/thrower. It was sidewalk size...~6ft wide blower...If anyone has any ideas on what manufactures made these I would appreciate it...Thanks for your time.