Let me be clear - I would never, in a million years, recommend a sub 3,000 lumen projector for this type of setup. It would be a waste of money.
Contrast ratios don't matter in business.
That is, manufacturer specified maximum contrast ratios mean nothing without proper light control. A single candle in a home theater can turn a 1,000:1 contrast ratio into a 50:1 contrast ratio! It's all about lumens once there is light in the room.
The Supernova is a very expensive screen... But, it's also unlike anything you've ever seen before. I'm sorry for those who have not personally witnessed what that screen looks like for themselves, but frankly, nobody who hasn't seen it should make any statements about whether or not it makes sense.
In this environment, it not only makes sense, it is the difference between something which looks 'typical' to something which can look spectacular.
The DNP Supernova Core screen can be had for between $2,000 to $2,500 for 100-120" 16:9 diagonals.
Throw in a projector from near the top of this list...
http://www.projectorcentral.com/projectors.cfm?g=1&hide=0&st=1&mfg=&p=1200&p=3000&w=&r=&br=&ll=&t=&db=&dt=&c=&ar=Wide+(16:9-10)&dvi=2&td=&i=d&is=&sort=brt&sz=15
And you will be very happy with the results.
We actually use the top projector on that list in our office. The Sanyo. We've put it head to head with a long list of different projectors and it is far closer to full specification for brightness and despite some visible screen door, it produces accurate colors and has solid video handling capabilities.
We've also used it with the Supernova and we've tested other projectors with the Supernova. The difference in our non-light controlled training room is astounding when using our normal matte white screen and using the Supernova.
Bottom line, if I were to get a projection setup, for his exact situation and the 80" Sharp wouldn't cut the mustard, then I would go with a 110" 16:9 Supernova and most likely the Sanyo PLC-WM4500.
On a budget I might go ahead and try out the Optoma TH1060p.