I'm looking for that soundtrack in good quality. I already have 128kbit version.
Ashita no Nadja (Tomorrow's Nadja) Music Box Series BGM Collection Animation Soundtrack [CD] (http://www.cdjapan.co.jp/detailview.html?KEY=MJCG-80135)

You can download that OST here
www.manga-no-haru.net (http://www.manga-no-haru.net/ashita_no_nadja___music_box_bgm_collection_2_ost__ s3619.html)