If you go to Belgium, don't forget to visit Antwerp, it's by far our most spectacular railway station, Trains stopping at 3 different levels, which can all be seen from 1 point if you pick the right location
if you want more information regarding train compositions you can always check
http://www.beluxtrains.net , which is mostly correct, do pay attention there are quite some timetable changes 9 december, which will have their effect on the train compositions
the trains in the Knokke/Blankenberge - Bruges - Brussels - Hasselt - Tongeren line are indeed mostly operated by M6 double decker coaches and HLE18 or HLE27 locos, which combine/Split in Bruges using automatic couplers (except for some off peak services operated by AM96 emu's)
The M6 compositions are used in split/combination services aswell on certain De Panne/ Kortrijk - Ghent - Brussels Airport - Antwerp services during peak hours
If you are lucky you can still catch some old red EMU's which will all vanish in the coming year, the old 1962 stock (1xx and 2xx) are expected to go in december but the 1974 stock (8xx) will still soldier on for their last years, while the remaining red 1986 stock (9xx) are now all beeing refurbish as rubber duckies