I now have a tractor that I use for snow duty but for years a used a 400cc Honda 4-wheeler and it was a lot of fun to plow. In 10 or more years there was prob only 2 major snow storms that I couldn't plow and that was due to ground clearance.
It really doesn't even matter what kind of ATV you get as long as it's 4-wheel drive. My neighbor has the Kawa Mule but has traction probs cause it's 2-wheel drive so he needs chains and that's a pia. The RZR seems like it would be great at plowing but not nearly as much fun as a quad like the Sportsman...Quads are even more fun in the snow than on the dirt, I've even taken mine on frozen lakes and it is a blast.
Consider this when buying any ATV for plow duty...
1) 4-wheel drive - selectable 2wd/4wd = more fun
2) ground clearance
3) vehicle weight - heavier is better
4) plow design
The type of plow and how it was engineered will make a big difference. Does it have a quick attach/disconnect feature. Do the attachment brackets that stay on the vehicle reduce ground clearance when the plow is off. How easily does the blade angle...stuff like that.
I do recommend a winch for whatever you get, sometimes a life savor for you and others but is great at lifting and lowering plow into any position.
One drawback is that the light duty plow will tend to ride over snow thats gotten packed down like from tire tracks. Obviously, it's best to plow virgin snow. Perhaps the RZR or others offer a "down pressure system", I suspect they do.
Also, just bundle up and don't worry bout cab enclosures, if it snow's that much in your area, an old beater p/u with plow prob would be best...just not as much fun!