I can think of several places where you can order online and either get delivered or pickup from their store/depot. Never used jessops. If possible worth doing otherwise check out for restocking fees and return post and packaging calling hotlines for returns.
Some online stores by the time you paid p and p and waited for the parcel the difference is not worth the hassle. Been there and got the t shirt
I know in London a bit of shopping around,for most electrical goods the savings if you go to the right store (not the chains) will be only a little more expensive if at all. Plus i know the camera works, all the bits are with it and its the model i was looking for.
Also make sure that you dont get a grey import. Seen to good to be true deals on various electrical goods but when you look closer theres a reason for it.