my first advice would be not to buy from jessops, as they are incredibly expensive (but a GREAT example when convincing parents/partners that you're getting a great deal on your new camera "its £800 cheaper than at jessops dad!"

) but as you've pricematched it shouldn't be too bad. never buy at their RRP tho
best thing to do is look thru the reviews on different cameras, maybe older cameras that have now come down in price as they'll be replaced and see what deals you can get. for instance, on the
www.camuser.co.uk website (and magazine, as camuser wont put up reviews from the last year or so on their site) the bottom section will mainly detail the important info as to picture quality, for instance chroma crosstalk, grain etc. they'll put in brackets whether its good, excellent etc. then you can check up the models that are in your pricerange and find out how they score simply on picture quality alone.
sound quality doesn't seem to change THAT much as cameras at that range will use basic inbuilt mics, so i'd buy a camera that allowed you to use an ext.mic in the future, as not all offer this function.
dixons are idiots. ignore anything they ever say

what they're saying basically is, their commision on the camera between a £500 model (ie £400 if u shop around) and a £650 (ie £450 if u shop around ) would be "massive"
all consumer cameras are laden with features nobody really wants, and are simply there to make the camera look like it does more than shoot video. some people find em useful, but its depending on features. you're not going to escape it unless you shell out a load of money (and even so, the £2000 RRP sony trv950 last year has a bluetooth web browser on it.. now how many people are likely to need that ?

) so just ignore them and look up lens/picture quality information only.