Powerex 2700 mAH AA

I have tried most makes of rechargeable batteries and most disappoint because after a while they can only retain their charge for a short period. I have been using two sets of Powerex AA 2700 NiMH with my Canon PS A650 camera and they last ages. I went away on a three week holiday over Christmas and filled three 4 gig memory cards on the two sets of batteries with no recharging - these batteries are over two years old and have been used on and off over that period - sometimes being left for three/four month without any useage. I bought mine at Maplins for £12 (for 4) but they seem to have discontinued them and only stock their own brand and Energiser both of which are feeble in comparison. Bring back Powerex Mr Maplin because they are hard to find otherwise. Nevada-on-line are a rip off because they charge £5 postage on a £14 product! I can just justify them at £14 for a set but beyond that is absurd. Why do no high street shops sell them?