One more question: I've heard that HID bulbs don't fit into stock MS6 fogs because of the anti-glare cover that's inside them. Since I won't consider removing it (for the same glare issue), is there any brand of HIDs that would fit as they are?
It's not the best idea, especially with your fogs not being projectors. As for the heat, I've run 50w HID's in my fogs with no problems. 55w HID's can actually put out less heat than 55w halogen bulbs.