Hybrid 4 or Fusion 3

I am female 5ft 6in weigh 10 stone and a side sleeper. Have no specific back problems can be a bit stiff in the mornings but obviously I don't want to buy a bed that will give me back ache! I have been looking at the Temper Cloud and the Dunlopillo Millenium in Furniture Village, like them both but can't decide. Would I sink in as much on your hybrid as I did with the Tempur? Which would be the better option?