Might I suggest the Airnimal Chameleon. Tyres are a bit smaller, at 24" but it's designed totally for road use and is high specced right up to 105 level.

A lot of people will say 'there's nothing wrong with 20" wheels' in a moment, and they're right, but if you've already made your mind up this is about the best on the market.



http://www.airnimal.eu/Chameleon/