the brakes are piddly, get some bigger ones on and be done with it

you don't need to worry about pads etc if you are going to go big but if you want to stick to standard wheels then a 280 is about the biggest you are going to get

2wd cossie discs, 4wd calipers
bit of spacing
job done

the added mechanical advantage of the bigger stoppers will far outweigh the hot/cold arguement even if you use really shitty motor factor pads as you've got twice the surface area to paly with effectivly