Hip and shoulder pain

Hi, I have read through your site and I am interested to know what you would recommend for my shoulder and hip pain, which I would say is down to my medium firm sprung mattress with solid divan base? I am now after a king sized comfortable base/mattress. I had latex before with slat base before which was fab for me then I downsized to what I have now double bed with sprung mattress and solid divan base (uncomfortable and I hate it) , and need to change as where I am lying on my side my shoulders are pushing into my body and it is very uncomfortable. Any suggestions for base & mattress etc would be great! Both myself and my partner are currently 15 stone and on diets, I am 5ft 7 and he is 5ft 11?