I am firmly of the view that the C2W limit of £1000, even if you add a bit on, is way below what you need for a good full suss. Any full suss at that price point will be heavy, and have low grade kit that will not perform well or last long. If you are just intending it for shortish rides on well made tracks it would be fine, but if you are going to properly rag it round the hills go for a reasonable hardtail.
I am guessing you will have to go for a mainstream brand as your C2W will need to be through an authorised bike shop. The upside is it will be easier to sell if you ever want to upgrade. Avoid Halfrauds if at all possible