In order to install any grab bars you really should install blocking behind the wall. Many times they are added but you then need wall anchors and such. Is this an existing bathroom or under construction?

Thank you millworkman for your reply. The bathroom is under construction and blocking has been added in the wall already.

I would use a series of grab bars or a stainless steel schedule 40 pipe like a commercial handrail with brackets. Look at CR Laurence under handrail systems.