While you may be set on a 2 post lift, the Bend Pak full height scissor lift provides full access and height while not having two posts in your way when not used.
I have the SP-7X. A further advantage, since you are building new, is to build the scissor lift in flush with the floor. The drawback being that it lowers the effective lifting height.
BendPak SP-7X Scissor Lift, 7,000 Lb. Capacity, Frame Engaging