Can't complain about the EU headlamps, they're great. I think they were $600 if memory serves?? I agree, the stock headlamps with halogen are suckysucky. They're good with LED replacements but then they're a little "too" good; too good for oncoming drivers if you get my drift. Biggest benefit was they'd light-up PoPo on roadsides like frig'n Christmas Trees.
It's easy enough to wire up a relay system for the fogs. When the brights receive power, that power would trigger a relay to send power to the fogs... now you're running everything. But I warn, you have to run independent wiring to augment (not replace) what's there. The stock wiring won't likely support the wattage of everything; even with the reduced needs of LED. The LL-AA-SS-TT thing you want to do is melt a wire harness.
I've seen deer here, actually stop at the side of the road and watch traffic. Of course, some only do that just run right out in front of car/truck anyway. Blinding headlights combined with SUPER sensitive hearing can throw off their ability to judge distance and speed. Might want to hire Elmer Fudd and/or Wile E. Coyote.