I got all my material from:

passive components: www.conrad.de o.ä.

integrated circuits: www.w-r-e.de/shop/index.html

If a IR receiver TSOP7000 is needed: www.spoerle.de

www.spoerle.de/de/part_search_result

(rem.: on 5.4.03 you have to buy at least 10 pieces, but this is cheaper than B&O)