Engine swap out for a 1.8t seems obvious choice, yes Audi and Skoda lumps are all 99% the same. Is yours a cable or drive by wire throttle?
It'll mean dropping most of the front end, transmission, driveshafts, hubs, brakes etc. Obvious things like the ECU, but I forget what else tbh. I'm sure there's plenty of threads and guidance in the mk4 section!
Check out the implications on your insurance first
I know you're already committed, but general thinking is that it's easier to just start with a 1.8t...