I like this. A few random points:
I think an important question would be whether the two-party system is as entrenched in this scenario as IRL. If not, people like James Prior might have a chance at winning.
A Richard Branson candidacy would be really funny. Not exactly the best equivalent to Perot, but I like it.
David Cameron != Mitt Romney in any sense, other than them both being rich. Given the Tories there are plenty of rich people to fill this role 
. I'm not sure who's the best British equivalent of Romney. Some relatively bland center-right person who's essentially a generic Conservative in positions?
nah i'd say romney and cameron are about equivalent for their countries.
Being a flip-flopping rich guy, Mitt Romney's basically the embodiment of our coalition.
