The Royal Ortho (orthopaedic) divan means the mattress is an extra firm; it is not based on any medical or other common standard, nor does it mean the bed has been professionally assessed or recommended. It is a term loosely used by manufacturers to refer to extra firm models in their range. Firmness is not determined by price, although comfort, luxury and durability and added features such as adjustability come with higher price tags.
The 1000 Classic mattress is not term orthopaedic, therefore, will feel less firm than the Royal Ortho.
When considering the firmess of the mattress you also need to take account of the base that you will be putting it on. A solid base will give the mattress a firm feel, whereas a sprung base will act as a shock absorber.
Both mattress are single sided, easy care mattresses. They will only need to be rotated from top to bottom.