My pleasure. The JVC indeed rules the roost on overall contrast ratio (it has very low black level). Its pixel fidelity though is not as good as DLP projectors which have simple mirrors that reflect light. But I doubt that would be a concern.Thank you. the flatpanel wont work since this needs to go up into the ceiling. However, at 23.5 feet, it projects 8.4 feet by your reckoning, and the actual diagonal is a little over 9 feet. As for brightness, we shall see if the JVC is up to it...i am told it is not the highest lumens but it has exceptionally good contrast for the price. Thanks again for advising here, as we've never investigated before.
My recommendation is to make all of this the responsibility of your AV guy to get right. There are a lot of ins and outs to fit a projector and screen to a space and you want him to be responsible to satisfy you. The moment you second guess what he is going to do, if it doesn't work out, he will just say you told him to do it.