[Sussex] Projector Recommendations

[Fay Zee]

Could anyone recommend a ceiling-mounted projector for a room 28ft by
14ft with a 7ft ceiling? (In metric that's 8.5m by 4.25m by 2.13m
high). The only windows are at either end and there are good blinds.
I've done some research but there are so many hundreds on the market.
Weight is not a consideration but the cost of replacement bulbs may
be. I'm unsure how many "lumens" would be appropriate.

It will run off a laptop which is non-widescreen.
The screen will be a pull-down at one end of the room. Not sure of
size or type.
Usage will be mainly software training.
Budget is £400-£600.

In other words, if you were kitting this room out on a reasonable
budget, what would you want to buy?

Thanks in advance,
Fay