Mine is one from an originally dutch registered car, but you're right, there are probably very few separate engines available in Europe.
But prices are so low for these engines ($200-$300 range in the US) compared to porsche 6-bangers, that even including shipping, it would still be relatively low budget.
But availability aside, I mean: a 6-cylinder type 4

Just how cool is that!
The funny thing is: 'they' struggle with the same (tuning) issues as us VW mentals do