Setting up home theatre dilema....any suggestions??

Here is my dilema.


I currently have an Optoma H31 and 92 inch graywolf....very happy with both. I am in the process of moving everything to a new room and is unfinished at this point but will be a multi-purpose room serving mainly as my Home Theatre.


My issue is I am trying to determine the distance at which to setup my ceiling mount. I have a length of 15.5 feet to play with. I eventually would like to upgrade to a 780p PJ at some point and maybe a 106" screen. Either the HD72, AE900U or Z4......havent decided.


Whats a good position that I can place the ceiling mount so that it will be fine with whatever choice I eventually make and also still good for the H31 and 92 incher at the moment.


Any thoughts.....oh btw I'm awfull trying to get the distance calculator to work.


Any help would be greatly appreciated.


Thanks.