RE: 4 season tent
A couple of things to consider when looking for a four season tent. Will you be back packing with it, then weight will and packability will be an issue. How many people will be using it at one time. A four season tent should be a dome style to shed snow, domes also allow you to sit up inside realativly easy. You will also want a vestibule as part of your rain fly, this will let you cook and store gear outside of the living compartment but also keep stuff out of the elemnts. REI is a good place to start looking, Cabela's also has a good selection.