Mattress for Arthritis and weight difference

Dear Sirs Thank you for posting all these information on your website. I have learned a lot and now understand why there are so many inferiour mattresses are on sale in the UK. Nearly 30 years ago we bought a compete bed in Germany and it was fabulous. The slats were individually movable and I could raise it in the front and back, plus we each had our own type of mattress. So one person could sleep flat whilst the other could sit up in bed and read. Sadly as we had to move many times due to my husbands time in the Forces that the bed gave up as it was just too often dismantled and also the movers van had an accident and some parts were broken. Since then we have been buying beds in the UK and found that we are replacing the mattresses for us and the kids, now adults every 3 to 5 years. I now understand why, as we were taken in by all the glimmer and did not look under the hood so to speak (your speak in one of your posts). My hubby is 1.85 meter tall (5.11 feet) and 90 Kg weight. He suffers from back and shoulder pain. He likes to sleep on his back, but he tosses and turns a lot every night, snores and at times twitches a lot. I am 1.63 meters tall and 68 Kg weight. I suffer from arthritis which is getting worse. I like to sleep on my front and on my side, but due to the arthritis in my neck it nearly becomes possible to sleep on my preferred side and sleep a lot on my back. I do not move much once asleep. Our current bed is a zip lock and each mattress is 90 cm x 200 cm. It is on a solid divan base. We bought it about 7 years ago and paid nearly £1K for it. I need the space in bed and do not like being enclosed, also hubbys constant moving around whilst sleeping is disturbing my sleep, hence a big king size mattress is a no go. I put a foam topper on the bed about 4 years ago as I felt that the Sealy Deluxe mattresses were no longer supporting us and were bulging inwards. I could also feel the nobs where the mattress is tufted up. I like the foam but it is not working either anymore. Hubby does not like the foam at all. He prefers a harder mattress whist I prefer medium to soft. We are not getting any good sleep and are getting desperate. Budget: up to £3K for base and 2 mattresses and 2 toppers. I would like to keep my wrought iron headboard hence the total width has to be 180 cm. We like the length to be 200 cm (about 6.6 feet). I would like the slats be adjustable to be able to sit up in bed or have the legs elevated when needed. Some storage to the sides under the bed would be nice too. Can you help us find the right type of Mattresses for my husband and me?

Thank you!