If I had such a budget I'd go all prime other than the kit lens:
5DIII plus kit $ 3700
24 L II $ 1500
50 L $ 1400
135 L $ 1000
Alternatively, 35L + 85L along with the 135L
Hey that would be a pretty damn nice kit though.
Best lenses for a 5D3 or a 6D? Thats a highly subjective question.
What I'd do? A 16-35mm f2.8L ii, 70-200mm f2.8L is ii and if I could swing it, a 50L f1.2. I'd also try to get a 1.4x tele converter for the 70-200 too. - If you can't quite manage that, I know the 70-300mm f4-5.6L is also extremely good, in fact in my opinion very extremely good. Or of course the other 70-200's instead.
That would bring you probably close to your budget limit. But it would be an extremely useful piece of kit. My opinion - the new 24-70 isn't worth it but then again your not me so I can't judge that.