I'd have an S2000, for starter you can actually buy one! Kind of an unfair test in terms of performance and track handling, if the S2000 was treated to the same Mugen tuning/handling upgrades I'm sure it wouldn't be a walkover.
I agree with some of the comments on the site, I think this was a deliberate point made by 5th Gear to state that the UK market gets all the crap and Japan get a lot more performance........somehow I doubt anything will change, but we can hope.