There's a very good shop in Beveren, (B) that imports straight from Africa. In Lent (B), Neerpelt (B) etc are other good LFS's.
If you live close to the Dutch border, you might check out Verduijncichlids in Rotterdam, they have also quite a number of cats, including Dorads, Syno's, Tanganyikan and Malawian cats, Pims, L-numbers etc. They import and buy from Ruijnemans as well.
http://www.verduijncichlids.com
In Den Bosch (30 km north of the border north of Poppel and Turnhout) there's a LFS called VanHaren, they too have catfish, a few weeks ago they had Parauchenoglanis sp, to name an unusual one. They have Syno angelicus, notatus, eupterus, nigrita, decorus and the true nigriventris in stock etc etc. They had S brichardi some time ago too.
In Eindhoven (25 km north of the border, north of Hasselt, Neerpelt etc) there's a shop called Heevis, they have rare stuff often, I rescued a huge S angelicus there, but they had Neetropius taakree to name a rare fish. Dorads, Syno's etc too. In Deurne (east of Eindhoven) the Waterman has Giraffenoses and many shops get their stuff from Ruijnemans.
You can PM me for a list of telephone numbers etc