Sadly, none of this may be easy to sort out with those big treads of yours. There's some nuance to the boot/binding/riser interface that gets trickier with bigger feet. Flow/Nidecker make a nice binding but the XL size has greatly increased width (yes, strange, I know) over the L, creating a large amount of movement between boot (the few I've tried) and binding. Going with an L renders the easy in/out design useless. Now O-drives and Ride El Hefes (now A-10s) are nice options, but don't mate well with Bomber Power Plates because they exceed the footprint of the plate itself. Other risers may be different. The point is that you may need to try a few combos that you didn't expect.
+1 on @dhamann's Thraxis recommendation.