I called the manufacturer eight months ago about the difference between a greyhawk and firehawk and they basically said that the screens were made for different lighting situations and should give the same basic picture overall. I chose a greyhawk for my 107 inch screen because I got the PLV-70.
I put my hometheater together myself and by your question, I think you might be doing the same so below I will write some of the stuff I went through / learned during the process as my situation was similar to yours (you want to have "the best home theater in the world" at a 100-200k price. Feel free to ignore the stuff I am writing below as it is somewhat long
First, be honest with yourself about how much of an audiophile and videophile you are. Even though, you say you don't have a budget and you want the best of both, you are discovering how expensive this stuff really can be, so you do in fact, have a budget. If you don't need the world's best picture, you can get away with a modest projector (5-10 thousand) and spend the rest on an audio system if you are an audiophile or vice versa. Don't spend money for differences you cant perceive or do not really care about. Make your ht for you and not for someone else's approval.
That being said, you need to be aware that projectors and dvd players are evolving rapidly, and no matter how much you spend on a projector or dvd player today, there is a good chance you will really want to get a new one in three years because of HD. You are going to want to have a digital transmission of an HD signal to your projector and if you spend $30,000 on a projector today without the correct future inputs, and the projector is not upgradeable, you will be out of luck.
These are the reasons why I got the plv-70 today ($5,000 and does big screens well) and plan to upgrade my projector in 3 years despite being in the fortunate enough position to be able to spend more on a better projector today.
Other issues you may need to think about are screen size. Here is a good link --
http://www.dolby.com/movies/m.in.0009.screensize.html. Another limiting factor to your screen size may be your audio system. In general, you need to have a 50-60 degree angle between your main speakers and your seated position to get the best imaging out of them (they should also be placed 3'-6' away from the front wall for the same reason).
The speakers you purchase may be tall, which depending on your room, and whether you want the best possible performance from your speakers or not, you may have to raise your screen to a height which is uncomfortable to look at from your seated position. The best way to test this is to actually borrow a projector, and sit in the seats you are going to use for your HT and project a blank screen on the wall and move it to the maximum height where you are comfortable looking at the screen.
There is a bunch of other stuff I learned in the process of making my ht which I would be more than happy to share if you want to private message me.
