I'm gonna be a douche here and contradict what Sam just said (It's ok, we know each other!)
I would probably go with a stem swap instead, it's cheaper (£20 new), easier (7 bolts rather than having to remove grips etc), and will make a greater difference to the feel of the bike than the bars. Something around 90-110mm length and 35 degree rise would be a good shout. There's a few brands who will just stick a logo on the same forged stem from the Far East (which are more than up to the job) so you can probably pick one up from your local shop if you wanted to have a look before you buy. This is the sort of thing though: http://www.tartybikes.co.uk/26_inch_stems/bbb_forged/c41p11644.html