I’ve been looking into exactly the same thing, albeit using a £1k contribution from my work’s cycle scheme.
Check that a shop will definitely take a voucher in part payment, as some won’t. Evans and Paul’s are notable large retailers who will though – and who also have a large volume of sale bikes.
Being a hardtail fan, I’ve looked very hard at the Solaris, FF29 and Karate Monkey – which are fairly commonly available as custom or factory builds. Brief thoughts:
– Solaris: appears to be the most “rad” and looks a reasonable compromise of all factors (2,200g?); I’m a Cotic fanboy, so this would be front runner for me
– FF29: great reviews and lightest (>1,800g), currently available for £399
– Karate Monkey: very versatile, but less obvious VFM and heaviest (2,500g)
The hurlde I’ve yet to overcome is that my current Soul is so good and that it would cost a fair old chunk to move to one of these 29ers, even with the cycle scheme voucher discount (which isn’t that much when it’s capped at £1k).