Re-framing basement walls after flooding. Drain tile with no concrete?
My first concern would be why is the wall or slab leaking?  I would start there.  Make sure your foundation is sealed from the outside with a waterproof substance first.  As for the inside, if water get's in and runs down the wall you must have a gap between the framing and the wall to let it run into the drain tile.  I would not put my bottom plate on top of the gravel of the french drain.  You can bump the framing out in front of the drain but you will lose a lot of space that way. You could also mount brackets on the foundation to attach to the studs so it does not rest on the floor.  Or you can use wood spacers.  Your plan for pressure treated wood and wonder board is good but a bit over kill.  The key is to solve your water problem first.