I think that for every F-35 sold, the UK get a percentage due to development input. I've heard it said that if enough are sold we'll effectively get the F-35 for free because of the income generated.
Somehow I don't see that happening!! Besides F-35 was meant to enter service in 2014 or something like that... At worst I'm sure we could nail a lease of Super Hornets down... Of course that requires standing up to the US and somehow I don't think we are going to do that.
It's a shame because I really do think Britain would offer more to the US as an ally if it grew a back bone and also went down a maritime focused strategy...
Put it this way, you double our RAF or Army and we are still pathetic compared to the US versions... Double our Royal Navy... Even with current project muck ups I count that as 4 CVF's, 12 T45, 26 T26 (hehe!!), 14 Astute, 6-8 SSBN's, 6 LPH's, 4 Bulwark class, 6 Bay class..
That's actually not hideously far of American power project capabilites....
But I digress! To keep this legal here is a picture of one of Big and Expensives (BAE) ideas for the hull form of the vanguard replacement.