Best advice? Buy something second hand. Floyd equipped guitars are so not in with so many people, that their second hand value is low, and if you look and sniff around you can pick up killer guiatrs for that price range. Look for Jacksons, Ibanez' and esp's that are normally out of your price range. Easy. Also, go and try a whole bunch out at about 5-900£ in a shop, then go looking for models like the ones you like (note the spec).
Just make sure while buying of the following:
1)Take the bar, send the strings slack, then release. The guitar should WITHOUT FAIL return to the exact pitch you started in. Do the same pulling the bar up. If it fails to return to pitch, either the knife edges on the trem are gone, or the posts are knackered. Don't buy, or negaotiate a substantial discount to cover repairs, for instance, if you fall head over heals in love with the playability.
2)Check the neck for warping. Always.
3)...and all the other things you must check.
Other than that, get a double locking trem. Personally I am an ibanez nut, so can give you the advice that on older ibanez's you want to find RG5xx and S5xx's xx = random number. The new ibanez's have good trems across the whole range with good stability and nice feel, so for a newer guitar with kick ass floyd I'd go with them (and i think they are doing a neckthrough budget priced RG which I played a while back and it felt killer, bargain for the money).
James