with all the new rules on exporting plants I think the best thing to do is to search for supplies in your own country. But there are 2 that regularly get mentioned.

There is the common one that is just called Syringia vulgaris alba and another Flowerfesta White which I think is sold by Thopson and Morgan. Dont know if they export though.

Yes, we are just looking at the Czech websites. I think we will go for the common one for the moment - the Flowerfesta White is available over here but costs around £80 so we won't worry about that one!
Thanks for the help

wow that is expensive but I guess that depends on how big it is.