I'll vote for the Timberline 4 also. I have the T-2 and it is pretty snug for more than one person. A friend had the T-4 and, while it is a bit heavier, it gave a lot more room. Mine is marginal for winter camping, a snow load bows it down pretty far. However, I have had it since 1979 and it is still going strong (although I have had to water proof the floor and fly several times). Use a small tarp or sheet of plastic under the floor for maximum life span!
-WH-