Hi Crossford,
 
Thank you for your enquiry. At your bodyweight, the medium spring tension would give you the correct level of support.  All of our mattresses are suitable for all bases but with a slatted base, we would advise a barrier such as an old blanket or duvet to protect the underside of your mattress from indentation caused by the slats.  If the slats were further apart we would recommend placing MDF or Plywood over them but as yours are only 3cm apart you would be fine.
 

 
The Artisan Bespoke has the firmest feel in the upholstery layers of our Artisan range whereas the Artisan Naturals has medium comfort layers.  You do not say what your sleeping position is and this is important when deciding on a new mattress.  If you are a side sleeper, the Artisan Naturals would be a better choice as the firm comfort layers could cause pressure pains in the shoulders, hips and knees but if you sleep on your back then the Artisan Bespoke would be an ideal mattress.
 
I hope this was helpful and if you would like any further information or would like to discuss the suitability of any of our mattresses please do not hesitate to contact the office on 0161 437 4419.
 
Kind Regards
Michaela