Help deciding new mountain bike purchase.

Porkanbeans

Hello all, I'd be very gratefull to hear the opinions of those in the know about mountain bikes on what bike I should go for. I'll start by saying I'm a fitness freak who absolutely loves the idea of climbing, so I'm looking for something lightweight, also I want something I can ride all day in comfort (I quite like the idea of doing solo 12-24 hour endurance events!) and it definatelly has to be full sus as I recently did the north face trail at grizzdale on a HT and hated it!!! I also would like something that's relatively durable to be able to do said trails.

I've looked at and test ridden (albeit on tarmac in the local car park!!!) the dale rush 4, trek fuel ex 8, specialised stump elite, dale rize 4 and marin mount vision 5.8! I havent had a bike for over 10 years hence my need for advice on the most suitable bike. Your help would be very appreciated.

Thanks in advance.