That transaction's Z-value should be:
67927cd4db3a11cd954cf8903f65f1ddbd0e601cba1a3b74cf1136e53f509592
Very nice! The Sig-Hash is right!
Thank you very much, that helps :-)
I will now take a lot of time to dig through the BIP143!
I try to analyze the calculation alone and implement it in my code.
If I can't do it, I'll ask again here.
Many thanks to everyone who also helped here and posted helpful links :-)
Keep in mind that in the BIP143, the first two elements related to hashprevout and hashsequence are a concatenation of
all the prevouts and sequences in the transaction inputs (from first to last) respectively.
And everywhere that says "sha256 hash" for an element, they mean you need to do a double sha256 hash on it, as well as a another double hash on the whole byte sequence once you've assembled it.