Unless I'm misreading the advert, that first one looks like it sticks on so probably on top of the original. That would have to be mega for £180+.
The second advert sounds no better than the ebay ones, in fairness for the same price, but where it refers in the first review to the clips being fragile is exactly how the Chinese made caps are. The clips aren't as flexible as the OEM ones and if you aren't careful when fitting they can get stuck and snap. Exactly what happened to me on my first set.
Funnily enough, I have a spare set going which I don't need anymore, if you are interested let me know. If you are in or can be in the west London area I can show you. This is them on my last car: