Is that £1k for projector alone or to include screen etc.
£1k to spend on a pj gives you quite a bit of scope as there are quite a few in and below your budget as long as you only want a 720p projector.
There are a few 1080p machines starting to appear below £1k (Infocus X10 around £900)
However you may only need a 720p pj depending on what size screen you want,how close you intend to sit from the screen and what are you going to watch on your pj.
Is it hd material, skyhd= 720p, bluray & hddvd=up to 1080p,games = mainly 720p.
720p pj's below your budget are.
Planar PD7010 around £499 was over £1k a year ago.
Infocus IN78 around £700
Optoma HD75 around £700
Optoma HD65 around £450
The above are all DLP projectors and you have to find out if rainbow effect is a problem for you before you buy,so get a demo.
Sanyo Z5 around £650,new model out soon
Panasonic AX200 around £700 but a new AX300 out soon probably £900ish.
There is a lot more info you need to bone up on to make a good informed choice,but then thats half the fun of buying init