I have to agree with Paul on this one. Not too many guys would tell you that daily driving a rig on anything bigger then 33's is a good idea, but you could go up to 35's like Will and Kevin and be ok. If you are thinking full width, 36+" tires, etc... you should look into a beater. You are going to need something to go get parts in, and your going to need something to get back and forth to work when you break your Jeep, and no matter how well you build it, if you wheel it, you will break it. Just look at how many guys have a second car, it almost becomes a necessity at some point.
I know the low pay= few parts at a time. I was an E-1 when I bought my first Jeep. You might want to consider upgrades that you can afford and keep wheeling. I have about $11K into my Jeep with the purchase, lift, tires, and many, many upgrades. That $11K has been over the past 9 years so it has been a little more affordable (about $100 a month).
Good MT tires(in the 33-35" size), a ford 8.8 or D44 rear and a locker (or 2) will allow you to wheel any trail I have been on over the past year. After seeing how Ed's axle shaft looked when in snapped, a D35 upgrade is a must.