Mattress Advice Please

meridian

Advice welcomed. I have a Hypnos guest bed in my spare room which is very comfortable. one of the mattresses was under leak from room above, it dried out but its stained so need to replace. Bed is slept on about 6 weeks a year by adults of varying sizes. Hypnos mattress is probably pocket spring and is 18cm deep, right now budget is stretched and would like to spend £80-£120 ish if poss, tried a basic £50 one at local store, it was really poor, have seen M&S do one for £90 approx and JL have one at £50 all these are open coil, I also saw one called postureform deluxe by breasley which comes rolled up, I lay on it and it was quite comfortable
man in shop said doesnt get hot and that it would be more comfortable than basic open coil. it appears to be reflex foam, thanks!:A