You need to tell us more about what you want to achieve with your car. If you just intend running standard software then there is no need to change. However, if you intend pushing the car as far as it will go then an intake is needed. The Revo seems to be the intake of choice at the moment. Sleek pipework at a good diameter with the least joins.
If you want to go to a stage 2 map then you will have to get a good cold air intake, (CAI), you already have a good basis right there with you turbo back exhaust with sport cat, you could be looking at 270/280bhp with a decent inter-cooler and cai.
Also a cai will move the filter area that sits directly on top of a hot engine and re route around the side of the engine to keep air intake temperatures down off which is essential when running higher boost pressures as this creates hotter air.
I had one fitted to my S3, no rubbing. I suspect it's a DIYer not fitting it correctly as they supply the brackets to clear cables and pipes. I can recommended this intake if you're after something quiet as I ran two open intakes on mine (tarmac venom & revo) and both were way too noisy for my old ears. Also, although they both made good power at the top end, I noticed a loss of early spool after fitting them, but no such issues with the closed VWR intake.