Nope!
The RS4 style wheels fitted to the A2 are not the pukka RS4 wheel.
The genuine article was actually an 18" wheel anyway and 8" in width as you rightly say. Also, the A4 (and hence the S4 and RS4) has always had a PCD of 112mm, as opposed to the 100mm of the A2.
The wheels advertised are not genuine RS4 wheels if they have ever been fitted to an A2. For proof, look for a part number in between the bolt holes (under the cap) which is raised and cast into the wheel.. Bet you don't find one!
Even though they are not genuine wheels, don;t be put off as the proper ones had a habit of bending, even more so than the A2 type. So much was with a problem, that Audi agreed to change the wheels every time they got bent, for the entire life of the vehicle, as long as it was with the original buyer.
Cheers,
Mike