Hello Toni,
Plans of the supertankers "Mundaca" and "Latona" can be purchased at
www.vth.deI haven't seen them so I can't say anything about the quality of the drawings, but they can be a start for your project.
As far as I know the company "Anker" made those plans. I don't know if the company still exists but if yes, they are from Denmark.
Graupner had plans of the Esso Berlin many years ago. They are from the 60'ies and on Ebay from time to time. The scale was 1:250. The plans show a nice old tanker but they are not very detailed. Also Graupner increased the depth a little bit to get the small model more stable.
I hope I could help you a little with those informations.
Kind Regards
Matt