Ok, first of all, you're right about TDKs, some of them are very bad.
There is nothing wrong with printable discs for archiving as far as I know, and the Verbatim Archival Grade discs only come in the printable variety - at least in Europe, as far as I know.
You're also correct about 8x Taiyo Yuden being generally better than 16x, particularly in the realm of DVD+R media. with -R there's not so much agreement. Unfortunately 8x Taiyo Yuden, particularly 8x +R is becoming quite rare but it can still be had if you know where to look
I have a 5 pack of "Verbatim Archival Grade" discs, and you could be right about them being made by Prodisc, on mine, the packaging says "Made In Taiwan" but the hub codes are clearly not from CMC MAG (the subcontractor for a lot of Verbatim media in Taiwan) so it can only be either Ritek or Prodisc.
Verbatim Archival Grade 8x DVD-R, as well as Taiyo Yuden 8x DVD+R, are the only two media types I would recommend for archival use - they are worth the money but you could also look at the TY 8x DVD+Rs, media code YUDEN000 T02.
I got my YUDEN000 T02s in a 100 pack from digitalpromo.co.uk
The full face printable discs I got are out of stock now, but they still have some unbranded (plain top) discs also in a 100 pack and they ship to Germany.
Another store I like a lot is GenesysDTP in the U.S. Shipping to Europe is obviously a good deal more than if the shop were nearby, but for what these guys have, it's worth it.