Replacing a 19 year old Sleepeezee Malvern mattress

Hi John, just read your piece on “Soft, Medium or Firm Mattresses” and I would be very grateful for your opinion.
I am looking for a new bed as our current one is 19 years old and although I’ve loved it for all those years, it is time to replace it. It is a Sleepeezee Malvern bought in Scotland. The first time I lay down on this bed, I knew it was exactly right for me and I’ve never regretted it.
However, now I’m facing a dilemma (all due to your website of course!) because I want to buy a good bed as this will probably be our last bed. I weigh 17.4 stone and my husband is 13.7. I would have preferred a single bed but a zip-link would probably be better because we’d struggle to turn the mattress (I want a superking).
Our budget is around £1200 and I would appreciate it if you could tell me what type of bed we need. I prefer a bed that’s not hard but, equally, I don’t like an over-soft bed. I want the softness with the support.
My husband doesn’t mind, except a very hard bed. I had looked at the latex bed but after speaking to Julie this afternoon, I don’t think this is going to be the right bed for us. My concern with the latex bed is that I worry how long this bed will support me. I’ve read some confusing reviews about latex beds and now I’m in a quandary! Please help!