Most likely the sellers entire flock of all poultry would need to be quarantined and bloodwork taken and tested for diseases.This would not be cheep,and even tho the birds may pass all quarantine requirements to enter your country,,that does not guarantee the birds will then pass your countries import requirements.Not to mention the possibility of losing them from the long distance shipping.Your looking at some very serious coin to achieve getting these birds to you with considerable risk. I happen to have 1 male midnight B/S and 4 midnight B/S hens for him this spring.I also have a nice 2 yr old silver pied male,still undecided who I'll pair him with yet.Ever consider shipping fertile hatching eggs overnight? The sellers flock would still need to be tested,ect,and import permits along with export permits would need to coincide on both ends.
I think there is someone in the UK with midnight blackshoulder. I will see if I can find his website and post it here for you. Since you're both in the EU, it would be more beneficial and cost effective for you to deal with him.
There is also one in Italy. He breeds many of the colours available in North america, just not necessarily in all the patterns. Here is his site http://www.pavoniec.it/
If you are interested in the silver pieds, and have the patience and time, you could breed them using pied and white eyed birds. Check out other threads for some of the details on how to breed for them. I know that both of those are available in europe as well.