EXACTLY! That's why I was asking those questions. Here's an idea for the VX (I'd be of no help regarding the FJ - maybe contact Jay Dunford thru the forum.) Tell me if you like this idea or not... the thin and flimsy tube bumper thingy behind the front cladding...
...could be replaced by a decent piece of square tube steel and bolted in its location, I believe. You could then tie in that stock vertical piece in front of it with a little effort. The bumper cladding would need a bit of a trim at the ventilation openings beside the license plate. Then tho the D-mounts could protrude thru those openings and you would otherwise have a stock appearing VX. Thru the process you could also choose to complicate things by incorporating a front hitch mount for a removable winch mount, a hook, a tow ball (which helps maneuvering trailers), and/or a flip-down license plate/front step... let me know if I confused you...
Anyway, I think figuring out what sort of mounting option you will have for the D-mounts should be done before picking out the mounts themselves. If you have to use round tubing then you would want the longer D-mounts, if you use the low-profile mounts you may not have enough room between the cladding and the D-rings. In any case, I would stay away from the 1/2" thick options and only look at the widest ones you can fit into the D-ring... lateral load precaution. I hope this helps you!