Renee,
The 47" snowblower for the 4100 is the same snowblower that is used on the 400 series lawn & garden tractors. It's two stage, and it works very well. I got to use it quite a bit this winter, and I'm very impressed with it's ability. Having said that, the one complaint I have about it is that I think it's about 6" too narrow for my 4100hydro. My back wheels are in the wide position, and the snowblower just barely covers my tracks. I'll also point out that the way you drive it makes a difference too, that is you can overcome that "limitation" - and I'll also point out that my neighbor thinks I have an outstanding setup, and that maybe I'm being a wee bit picky about this... but, if I could wave my magic wand, I'd make it about 3" wider on each side.
The snowblower mounts on what's called a quick-tatch hitch that's mounted on the front of the tractor. I also have a rotary broom and a small blade that fits the quick-tatch, but if I were only going to use the one implement then maybe a rear blower would be better. The problem with a rear-mount is that you drive backwards to operate it - get's tiresome after a while. I'm not familiar with the rear snowblower, so I can't tell you how good/bad/indifferent it is. Whichever you decide on, I'd highly recomend that you get the remote chute rotation and remote discharge cap control. My chute rotation is hydraulic, and the discharge cap is cable operated. Getting off the tractor to adjust rotation and discharge angle would get old very fast...and you'd waste a lot of time doing it. I can adjust mine on the fly - makes it real nice and easy to put the snow where you want it.
I have several posts on here - click on my name and then show all posts and you can see the various posts. I recall that I do have a pic in the photos forum under "Never give up snowblowing" - shows me cutting into 4-1/2 foot drift with the snowblower. Like a said, it's a tough beast...
I see that you are near Concord, NH. I live in western NH, near Claremont. If you'd like to stop by, I'd be more than glad to show my rig, answer any questions, etc. I'm pretty flexible time wise - just let me know if you are interested.
I hope this helps some. If I can answer any other questions, please ask.
Dave Wells