In reply to coinneach:
Can you choose the retailer? That could be the deciding factor what you can get.
Hard tail or full suss?
Did you try renting a bike?
I got a 29" hardtail with 100mm travel (Scott Scale 950 2016) and I am more than happy with it. Got a bit disappointed that £1k bike still has unsealed bearings, something I didn't know about and did't think of. A year later I upgraded the shifters to XT which seems like the best upgrade to the bike so far. I do long rides, so I feel like 2x10 gearing suits me better.
Keep in mind that some schemes let you go over the £1k mark, you just pay anything over £1k straight away.