Sounds like a good bet - bit risky though in terms of an injury or an accident can rule a rider out of a GT. Maybe the bet could take this into account?
Like LA lived for the Tour and that was that, no real commitments elsewhere over the season. Froome looks a more rounded rider who will be taking on classics, doubling up the GTs etc. so more of a risk he'll misfire or be injured one year. He's in a league of his own though right now.
Think Quintana is going to be dominating the next few TDFs mate so I'd give that one a miss