I would go for Afghan Selection, Khalifa Genetics, TRSC or Indian Landrace Exchange. Everyone of these are pure landraces that are not worked, or atleast thats what they are telling you. I have grown ALOT of TRSC over the years and they are your best bet, ive also grown alot of what Afghan Selection have to offer and they havnt disappointed me yet. Remember that most afghan landrace seeds have quite a think shell and for the best germ rate you should punch them. Practise on some shit bagseeds before you do it on your precious landraces. Happy hunting 
Pz 