Feather and Black Supaking 7000 mattress

Hello chaps, I hope you can advise me on which mattress is best. I really want to purchase one but Im a bit confused. I am looking for a superking zip and link mattress. Definitely pocket spring as my current memory foam is awful. Its for myself and my partner. He is 6 foot and weighs 12.5 stone. Im 5 foot 6" and weigh just under 9 stone. We tried a couple of mattresses at Feather and Black to see which type we preferred. There is no way we could ever afford their mattresses but thought it was a good idea to check out what sort of 'feel' we liked. I am not sure if you are familiar with their tension scoring system, but I was given a set of figures for our preferred mattress and I am now trying to find a similar and hopefully cheaper mattress on your site that match as near as possible the 'feel' we liked at F&B. I really hope that you can help.. We liked the Supaking 7000 Spring count at tension 6 which felt soft to medium i think. They range their tensions from 1-9 and at 7000 springs we liked their tension no 6. Now I realise that is a way too expensive bed for us and maybe that sort of 'feel' of bed tension will always be beyond our price range. But I am still hoping and thought it best to ask.. you never know :) Given the information I provided (and I hope its been useful and translates) are there are similar 'feel' beds you can suggest from your site?

Our budget is £700 Thanks so much Amy budget - 500 medium to soft/Pocket springs high Feather and Black fave beds Zip and link supaking 17 000 spring count tension 5 (1 to 9) Supaking 7000 Spring count an tension 6