If you're determined to change the bed, I would leave the bed lip as is. I think your bed has a lip to keep the mattress in place, and removable panels
under the mattress. I would make the interior
area (the removable panel area, inside the lip) liftable. In other words, get rid of the removable panels
(or even a larger area inside the bed lip) and replace them with a single
liftable panel. Use strong enough struts to hold the mattress up when lifted. This would be much easier to make.
This is without knowing how your bed is. I hope it makes sense...