sounds like a tall list for only 1000.
when buying used, factor in the cost of a new bulb. you may get lucky, but there's no guarantees on the hours on the bulb in the machine when you get it, or how much longer it'll last.
personally, I don't like the idea of buying a used a projector, definitely not one in the 1000 and under range. figure a 1000 used projector would have cost about 2000 when new. that's not likely a projector built to last a long time. it's likely a projector built to deliver the best performance per dollar, possibly at the cost of reliability. then throw in the fact some owners will consider a 2000 projector disposable, they may not have taken great care of it.
if we were talking 20k projectors being sold for close to 10k used, that's a significant savings on a high end product built to last and probably taken care of by it's owners. less likely somebody's going to abuse a 20k purchase.
don't get me wrong, you've got options for 1000 or less. but I would expect to see large improvements with a small bump in your budget.
Displays: Samsung PN64F8500/JVC X35
AVR: Pioneer VSX-1130K, 7.1/5.1.2 audio
Sources: HTPC(Enby), PS3, XBOX360, Wii
Control: Harmony One