The only DSLRs worth considering for video are those from Canon. Since they only make one or two models in your price range, it should be pretty obvious to you which is the best for your needs. If you do with a Canon, be certain to download the free firmware upgrade from Magic Lantern. This FW upgrade installs a good deal of much needed features for video.
I'd avoid anything from Nikon because when it comes to focusing in video mode, Nikon's focusing system is inferior to that of Canon. This results in the camera randomly loosing focus.
You've asked for DSLR recommendations for videos, but in all honesty, Sony and Panasonic's mirrorless cameras are about 2-3 years ahead of Canon in terms of video performance, image quality and features.
A significant jump up from a mirrorless camera is an actual camcorder from Sony, Canon or Panasonic. At your price range, you can get a 4K camcorder that would outperform any DSLR at any price. If you wanted a DSLR that shoots 4K, you would need to spend an additional £900. So unless you absolutely need the narrow depth of field look, then you do not need a mirrorless or DSLR camera; get a camcorder instead.
There are many drawbacks in using a digital still camera with a video feature instead of using a purpose-built camcorder. Be certain to know what it's like to use a digital still camera for video before you buy. While image quality of the video is important, what's even more important is getting a device that won't inhibit you from getting the video.