You could order them directly from BIMARE
www.bimare.netThe boards should be quite reasonable.
You should get support from them, and I didn't had any bad experiences.
If the language is a Problem, maybe Catfan can help. (He posts here on the forum too and is somehow related with bimare)
Otherwise Matt from Vectorworks, you could maybe buy the boards across him. Vectoworks is according to the Website of Bimarethe the US Bimare Distributer.
Good luck