can you give me a estimate or price for the optical engine. I can not find anything on this part.

I would look into the Hitachi line of projectors or Epson. Hitachi projectors are very reliable and although the claim is not 24/7 they are definitely known for 8 hours a day, 5 days a week operation. I mention the Epson for a couple of reasons. For one, they receive a lot of projection awards, but in your case, they also have overnite support. So, if something happens to the projector then you can have a replacement there the next morning. Check into Epson. Their overnite replacement program is really designed around people that depend on their projectors to stay in business.