There is plenty of k03s about and are fairly cheap. from what I remember k04s are the more favourable so the prices reflects it, makes me laugh that my buddies Cupra Ibiza is running 210 ponies with a k04 from a 1.8 20v 😂
Welcome along buddy Like mentioned a bug eye rolla inlet mani with a 4efte throttle body and then a 4 branch is about as far as you can go without spending loads :-)