Five stone difference between us - which matttress?

Hi Guys - what a fantastic, honest and informative website :) Well after 10 years of a 700 Highgrove Pocket and then using a memory foam topper (wifes decision for bad back)its time to replace our mattress. Wife wants memory pocket sprung and I like Pocket Sprung Latex memory is well to hot for me. I am 14 Stone and my wife is 9 stone and I have no back problems. I have found a Healthbed 1000 Pocket Sprung Latex which the retailer is willing to split the bed and sell me the mattress for £425, but I think there is more discount in there. Id like to know if I'm shopping in the right direction?

Kind Regards Shaun >