You can get a perfectly relaible and light ish front suspension bike for around £300 that will be durable and pleasant to ride for a novice/intermediate rider. You dont want full suss for a charity road ride. If you need any help pm me as there are clearly too many 'experts' on here

ps. Can the KEITH please explain what is wrong with single pivot bikes please. Having owned at 4 multi link bikes over the years ( Giant ATX990, LTS, Kona Stinky and Rocky Mountain) i've just returned to a single pivot Santa Cruz and combined with the latest generation shocks it pedals far better than anything i've ever ridden AND less flexible laterally and a lot more robust and easy to maintain. The only better bikes IMO are the VPP bikes but to be honest I couldnt justify the extra cash because the performance just isnt 'that' much better. Pivot location and design is far more important. Most multi link bikes are basically a single pivot design that only use the linkage to drive the shock only anyway to give a rising or falling rate...........and i dont really count the 'horst link' or seatstay mounted 'horst' links as real multi link bikes either

THAT blue bike is a Unified rear triangle which is rubbish.......because when you stand up your weight is on the swingarm and your basically riding on a sprung hinge And when you sit down you bob around like a cork in the sea unless you massively overdamp the shock.