Look for a B8 wheel (make sure the part number doesn't start with 8P0 as chances are it won't fit as it's an A3). Pretty sure no B7 wheels came with an SLine badge.
Part number starts with 8K0 419 091 for the B8 or 8E0 419 091 for the B7 are these s-line ones, as audi say you have to buy another airbag for s-line ones as there different ? is that better
mines a 55 plate a4 3 spokeYou only need a new airbag if you are going from a 4-spoke to a 3-spoke or you get an A3 wheel.
To confuse matters, 05 and 06 cars will have a wheel with part number 8P0 419 091. I believe it was shared with the A3 and then around 07 the A3 used a different wheel, the B7 number then changed from 8P0 to 8E0