Hello! I have a few for you. Please try,
www.puerner.de (Internet), new stuff, Tillig, Beckmann TT, Roco TT, Piko TT, PMT, Modist, Kuehn, Kres, etc (new stuff: very good prices), the gentleman's name is Thomas Puerner, been dealing with him for over 10 years. Here's another shop that offers a big selection of new and secondhand-like new, but clean (up to 30% off and minus 16% VAT german tax), the name of the shop is "Michas Bahnhof", the owner's name is Micha. This shop you have to go in person since he does not list all his items on his web site. The address is: Nurnberger Strasse 24a, 10789 Berlin am Tauentzien (by Zoologisher Garten), all scales, all makes, American, European. Another one that is also over the Internet:
http://modellbahn-Discount.de, this one I've never tried it before, I suggest it is worth a try. This shop also over the Internet:
http://www.lokpavillon.de/shop/, I've tried before but a lot of back orders and they are very expensive, I think they are direct suppliers from the manufacturers, the delivery takes up to 3 months. This one I've never tried it before:
http://www.modellbahnshop-sebnitz.de/, very nice web site but I think they prefer bank transfers not credit cards, or if you have a chance to go there in person, I think this store is owned by the Tillig company. I hope you find these very helpfull.
Best wishes.