Hi do you have a showroom where I can test mattress? I'm 18 stones and 6ft tall, I've had a ultra firm mattress for the past 4 years and recently purchased a relaxsen mattress from Italy, I had one back in the 90s and was fine but this one feels too soft and now I waking up with a Lowe back pain as I'm sinking into it and arching, what mattress do you recommend for me? Need to get my back sorted!