I recommend 3 sources:
www.EdensBlooms.com
www.RoyalColors.com
www.AfricanAmaryllis.com
Since you are from the Netherlands, it seems like Royal Colors would be easiest for you.
As far as the availability of the specific varieties you mentioned, time will tell. We at EdensBlooms have tried to order Thai Thai several times. So far, Hadeco hasn't filled the order. AfricanAmaryllis is operated directly by Hadeco (or close affiliates) so they may offer it first. One of these years we will succeed in getting it.
Since Toscane is a Cybister it was probably developed by Ludwig & Co. Ludwig discontinued business last year (2010) and sold all their varieties to other growers. 2010 was a bust for Cybister varieties in general. My agent in the Netherlands said more
should be available in the fall of this year (2011), from the new growers.
I hope this information is helpful.
-Aaron