Well here's the first obvious question:
If you're getting a projector, why are you even using the TV? I use my projector for everything, movies, video games, HD TV, and SD TV, unless you have some specific reasoning, using that small TV when the bigger screen is available just seems silly.
Next That's about a 80"ish screen I think, now because you have vaulted ceilings a slide down screen probably won't work, unless you want to have it hanging in the air by either chains or probably poles (so it doesn't move) and that wouldn't be really pretty.
So your second option is something on a stand, but I don't know much about those.
It's possible, I'm not sure how good it'd look since you'd enver have it in *exactly* the same place / angle for the projector. It'd work, but it wouldn't be ideal. That's probably your best choice if you really want a moveable system.
- D
