I love these names. I went to school with a Polish girl called Marta and knew a Slovakian guy called Marek; both names have stayed in my memory. DC will have a German surname so these names would both fit. But how will they sound to English speakers? Especially Marta, which has almost the same sound as 'martyr'.
Keep on my list or ditch?!
(I'm not having twins by the way, but keeping sex of the baby a surprise)