and this one is very good. You've said that you don't want to be upgrading in 12 months time, and that you want to edit images and video. This computer will be ideal for that, and at the price quoted I think you have a pretty good deal.
You could probably shave a few pounds off the price by tweaking the specification, or by shopping around, but that's a matter for you to decide. In my opinion the computer would do the job, and the price is a fair one.