The good news is you’ve plenty of choice. For £1300 you could get a light(ish) XC hardtail, or a slightly less light trail type hardtail..
For a grand, what about the Boardman pro 29er?
Or look at the German direct sales bikes, Canyon, Rose, Radon (I’ve just got one of those)
Have fun deciding! It’s actually one of the best bits (imo)