Really confused by all the mattress choices

Wow, Wow, Wow……. What a fantastic website!
As a 49yr old divorced lady I decided it was time to get rid of my (embarrassingly) 15yr old kingsize bed and invest in a new one. My current one is a Simmons Silver Season tufted 1200 pocket sprung with a pillow top for a supposed warmer side and a laytex side supposedly to be cooler when flipped over (although I have never noticed any difference). When purchased (from Dreams) this cost £1,200.00 which was a lot of money 15yrs ago. My budget now is in the region of £700.
Anyway, today I paid a visit to my local Benson for Beds with the intention of just sitting on each bed to find my ‘comfort zone’
I knew I did not want a memory foam as I had heard from several people that they made you hot in the night and as someone who already has the fan running all night long, that was the last thing I needed.
After laying on 4-5 beds I found a Sealy 1800 pocket sprung in ‘zone’ 3 that seemed ok and I asked the salesman to see if it came without drawers, while he went away I looked at the height of the bed and decided it was rather low down to the floor (my current one measures 28″ from floor to mattress which I like) and the one next to it looked nicer, it sat on it and it felt really, really comfortable.
The salesman came over and said ‘that is a memory Sensaform zone 2’ which just blew away everything I thought I wanted, so now I am even more confused!
I came home and started to investigate lots of websites and thank god I found yours! While I am still sifting through all the different areas of advice, I would just like to say well done for having such an informative site.
With best wishes
Karen