Front projection - DLP - 80 inches or so should do the trick I think.
You may want to look at the
Mitsubishi XD300U. Almost 2000 lumens and 4000 hours lamp life and 2000:1 contrast ratio. I was offered USD 2300 for this a while back. US prices are around USD 2900.
I sit approx. 13-feet from my screen (75-inches diagonal) and it looks fantastic. I have an LCD projector which is too bright (3300 lumens) but using DVD-RP82 progressive scan image and S-RGB mode, the results are wonderful. Also at 12-feet I cannot see the screendoor effect and mine is LCD. DLP projectors perform even better.
Projection screen size / distance calculator for the XD300U
You should be able to get atleast 78-100 inches if the projector is placed around 12-feet from screen. Mitsubishi projectors have S-RGB which is a very nice feature for color matching. The images are really more realistic when the S-RGB mode is turned on. There is a slight drop in brightness but it still looks great.
Plasma : Looks great but prices for larger ones are still prohibitive.
I am not a fan of rear projection sets although I haven't closely observed the latest models. Too grainy when viewed at close distances. Depending on the screen materials used in these, the angle of view can be very limiting at times.
Just my thoughts. Good luck with your decision.