Please re-read the Board info, it clearly states "No Piracy."
If you want a key, then contact the developers and make payment.
As for getting the SGML part. If you do not actually need the completeness of SGML then look for a decent XML application.
Maybe you can use DOCBOOK inplace of SGML.
I have used LINUXDOC then I switched to DOCBOOK/SGML then i have settled on using XML. Plus, I still make use of LaTeX.
If you are looking for a Freeware DTP, then look at Scribus