Another thing to consider is the limitations of the projector itself. According to the projector calculator on ProjectorCentral.com and data from Mitsubishi's website, your plan for a 76" screen with 16ft throw distance isn't going to work. The image is going to be too big at that throw distance. At 16 ft, the image is going to require at least a 110" screen. Or, the 76" screen is going to require a throw distance of no more than 11 ft.
Also, the 1000U has a fixed lens shift of about 33%. That means that for your stated screen (37" tall), the image offset is about 12". Therefore, the projector will have to be 12" BELOW the bottom edge of the screen or 12" ABOVE the top edge of the screen, depending on how it's mounted. Since you mentioned a throw distance of 16 ft, I presume that the projector will be behind you. If you plan to put it on a shelf behind you, the image will probably be too high to view comfortably if you plan to shoot it over your head. Ceiling mounting would work, though that's not the most convenient thing to do if you plan to put up and take down the projector every time you need use it.
In this case, then, your remaining options are:
(1) place the 1000U on a table in front of you to get the closer throw distance (though I don't know if that'd work for your particular setup).
(2) get a different projector with more flexible zoom and lens shift. If DLP isn't an absolute requirement, then there are 2 popular 720p LCD projectors (Panasonic AX100 and Sanyo PLV-Z5) that are much more flexible for placement. They are somewhat more expensive than the 1000U. The Z5 goes for around $1500-$1700, and the AX1000 for around $2000. However, I believe they both have $200 mail-in rebates until the end of December.
