Congrats on the new car.
There are catch can kits for the Mk7 around (eg Integrated Engineering & Burger Motorsport) but they are all made to suit the engine in the GTI/R and are stupid expensive for what they are.
As you mentioned, best bet with the 1.4TSI would be to piece one together yourself. I did a similar thing on my Audi SQ5 as nobody made a catch can kit for this car, so I purchased a good quality diesel catch can and made a mounting bracket, then routed 19mm ID tubes to the PCV.
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