Every LCD projector these days, as far as I know, has a zoom lens on it.
If you check
www.projectorcentral.com you will find close (but not always perfect!) throw distance ratios. The Panasonic has a 1:1 to 2:1 zoom lens - so you can mount it from (about) 102" to 204" away from your screen!
That makes the Panasonic one of the most versatile projectors to mount that is currently available, at that price.
You can probably expect that your projector will typically be mounted pretty close to dead overhead unless you are able to use a projector like the Panny and put it further away from the primary seating spot. I would likely go with the Panny or, if I could swing it, the new Sharp XV-2000 which uses a 1280x720 DLP chip.
You already own that 102" diagonal 16:9 screen?
Oh, and noise is always at least something of an issue, but with current projectors, fan noise is about as much as plasma noise. It just isn't that strong, and only noticable during near silent moments of films... dramatic pause.