Regarding the steps: you kinda have to determine the depth of the shelf first. That determines if the shelf will be the top step, or come off of a lower step. The steps would likely be different for each of those scenarios. We also need to have an idea where the slope to the deep end starts, and how deep that shallow end is, etc. That determines where the steps need to start and stop.
You or the contractor should be working with some sort of overhead drawing or rendering to help you design the shelf and steps. It's hard for us to help without that, and without all the dimensions involved...