Oops, did I read something in your post that you didn't write? Sorry man.
Strike most of my post above; I'd be willing to give these a shot.
If they do crap out, well, you didn't lose a lot, but if they hold up, you saved yourself a ton of cash. The price of the units above are really only justified in pro or critical applications where a proven design is absolutely mandatory... or if you just have the money to blow. For auxiliary lighting... why not give these a shot?
I've never heard of using a spotlight on one side (the side of oncoming traffic) and a flood on the other. Brilliant actually! I may have to borrow that idea.