For one reason or another - ok, for many reasons, I have lived 400-500 nights in a tent (well many tents I suppose). If you are planning on living in a tent in one place, GO BIG (or go home, lol). Seriously, a crappy $120 tent from Target is a great idea. Get a four person tent, or hell, even a family sized tent. You want to be able to walk around, stand up, not have the feeling of it being small, cramped, and the world falling down on you. Rig a tarp over the tent so it is even more waterproof. Then get a cot - being off the ground will make all the difference in long-term living. Here's a hint: things in a tent mildew and mold. A lot.
You do not need or want a four season tent. Besides being stupid expensive, they are meant for mountaineering and winter camping. I don't think you're planning a trip to Denali, so this won't be necessary. Tents left standing in one place for extended periods of time break down. The UV rays disintigrate the fabric, branches fall on them, animals chew through them. You do not want this happening to your $750 four season tent.
Once when I moved my tent after several months in one spot, I was surprised to see that there were mouse tunnels under it, as well as a freshly shed snakeskin. Yes, apparently I was sharing my home with others. The idea of tent living is glorious. The reality of it differs.