Depending on your room configuration I would suggest buying a HD projector (such as the Sanyo Z4 which is last years model now on clearance for around 1200USD I think) and buy a screen for max $300 (you could make your own for under $100) and you can have as big as a screen that you want!
Although anyone that I know that is thinking of buying a rear projection TV I suggest getting a front projection system first.
It really does look like you have a 100" plasma on the wall!
It will also depend on your lighting control in your room.
