A front angled blade would also take a 3rd function kit to be able to articulate the blade back and forth hydraulically. I can't say I've seen a front angled blade that was strictly manual adjust, but there must be one out there somewhere. An angled blade is going to want to "push" the front of the tractor sideways as you push the snow, more or less depending on how much angle you have on the blade. So a front blade may take more to get set up and running on your existing tractor than a box style snow pusher.
As far as a snow pusher goes, you can handle only as big of one as your traction allows. A smaller, lighter tractor will not be able to push as much snow, regardless of horse power, due to it's traction limitations. Adding things like tire chains and ballast weights will help that. I would want something at least as wide as the tractor tire track width as a minimum.
