Hi katherine,
 
Thank you for your question.
 
From the information you have provided, I would recommend you looking at our Artisan Luxury mattress which contains 100% natural fillings which gives the mattress a very soft comfort allowing you to sink into the mattress.   We would recommend that the mattress comes with a medium spring tension which is then going to give you the correct support for your body weight.   We do not normally recommend a firm spring for any one under 17.5st as the springs in a mattress need to move with your body weight in order to give you the support.

 
If you would prefer a mattress that has firmer upholstery layers, I would then recommend our Artisan Bespoke 004 which again has 100% natural fillings but with a firmer feel than the Artisan Luxury.   
 
Please see the attached comparison sheet which explains how each of our mattresses in the Artisan Range feel in the top layers and which of the Vi Spring mattresses they have a similar feel to.  It may be of benefit to you to try the Vi Spring mattresses in order to assess just how you would prefer the comfort layers to feel.
 
The feel of a mattress can also be different depending on the type of base the mattress is to go onto.  We generally pair our Artisan mattresses with a sprung divan base which supports the mattress making it more forgiving.  If the mattress goes on to a slatted or solid base, this will firm the mattress spring tension up.
 
I hope the above is of assistance to you but please do not hesitate to contact our office on 0161 437 4419 for further information / guidance.
Kind regards Julie