Plenty of good packs around. The Karrimor's pretty decent - maybe could be lighter - but have a look at the stuff from... Pod, Macpac, Mountain Equipment, Osprey - if you're feeling generous - and Lowe Alpine. Oh, and the Berghaus Extrem packs aren't bad either, albeit aimed mainly at climbers.
Most of the retailers in our shopping section have clearance sections which are worth a browse, though with something like a pack, you really want to try it on, with a load, before buying and see what suits you. Particularly relevant if you have an unusually long or short back since the Karrimor is one back length only, others have options.