You can get the Tanos version from Lee Valley. The T-Loc catch will be blue and the lid won't say Festool. You can change the catch by ordering a green one from Festool's parts department.
Yes. The attic takes up the space up inside the lid. So nothing can be sticking up higher than the sides of the bottom. Probably an 1/8" less just to be on the safe side. Also take note of the location of the front center lid projection and the small tabs that stick down into the bottom of the Systainer when planning spaces for things.