I have owned 6 LandCruisers throughout my driving life - since high school ;-) 3 FJ40s and 3 FJs (2006, 2008 & 2014). My current is my special ordered with all options Sandstone FJ with MT.
If you really want "operational" fog lights that really works, putting them on top of the stock bumpers is not the best placement for them. Why? Because the fog lights will be too high above the ground. Basically they will be about the same height as your head lights. Fog lights should be placed as low to the ground as possible to minimize back-scatter so it will not reflect back to the driver's eyes making the view worse than better.
In fact, I find traditional fog lights (lights that cost less than $400) are ineffective in dense fog and snow blizzard driving conditions. Why? The traditional fog light designs don't limit the top portion of the round light beam pattern that actually increases blinding glare in fog and heavy snow. My opinion is backed by my experience driving over 300,000 miles when I lived in the Upper Peninsula of Michigan where heavy dense fog and snow blizzards is common. To give you an idea, wind can be 30-45mph and snowfall can reach over 50" in a day! This is why I had to design my own fog light that would work in such harsh driving conditions.
There are three basic factors that determine how well a fog light will work:
(1) The location of the light (must be as low to the ground as possible). In fog and snow conditions, the light beam should only illuminate below the hood of your vehicle. If the light beam goes above it, the driver's vision is impaired by the glare from light scatter caused by the fog and reflection of the light back to the driver's eyes. The purpose of fog light is to pierce thru the fog and illuminate only objects in front of you and the road.
(2) The larger the reflector diameter is, the more more efficient of transferring and holding the light pattern further down the road. It is critical to maintain a consistent bright beam pattern.
(3) A euro-beam reflector design with a top beam cutoff pattern couple with 100W 2500K yellow bulbs (I use PIAA's Crystal Plasma-Ion 100W bulbs). This is a perfect combo.
TO save money and achieve performance, my recommendation is to buy Hella 700FF light kit (comes with two light housings and wiring kit - approx $80. This light is a little big (8" diameter), about the same diameter as your stock headlights. However, it has the correct beam pattern for fog. Also, ditch the stock bulbs and buy a pair of 100W equivalent H3 LED Yellow bulbs or Plasma-Ion 100W Yellow Bulbs (hard to get).
My setup is a TJM Bull Bar, Hella Rally 4000, and Hella 700FF.