build in stairs for a defender 110 back compartment

I am looking for a freelancer to build me a set of stairs for my defender 110 back compartment. I will need the stairs to be made of metal, as this material is the most resilient to wear and tear, and will last longer. I have a rough idea for what the design should look like, but am open to modifications and suggestions from the freelancer. Furthermore, I have some specific features in mind that I would like implemented into the stairs the stairs need to fit under the back compartment of a customer 110 Defender, pull out and slide back in, support a 200 lb dog, the stair needs to be 18 in wide with a no slip surface at least 10 in deep
and easily lock in for structural support. Expertise in this area appreciated as it will take imagination, innovation and thinking differently to achieve the solution thank you