New mattress used in B&B

We recently stayed at Taggart Guest House, Clevedon nr Bristol and the mattress was amazing!! We don't have any specifics of it though. The new mattress will go on a slatted base which we understand will need boarding. I have longstanding lower back degenerative disc disease. Our weight approx 10.5 / 12 stones. We prefer to have as much natural fibre content as possible. Please advise.