I'd recommend something Windows mobile compatiable so you can easily update or change the software. I have been happy with my Mio 168 which are now cheap as chips.
This looks a good deal for £109...
Have a search for 'Acer n35 GPS handheld Pocket Chauffeur' and you will find what looks to be a good deal.
to be honest id go for a garmin.
you can get the speed camera pois and it seems a very nice unit
comet at one point were doing the i3 at £99
and i think the carphonewarehouse had them for that price too
hiya mate .. i would buy the tomtom as it has never got me lost .lol. not a bad price at comet 160 quid and you can get all the speed cameras put on it . also never leave the stand in your window !!