In the meantime, if you're working on Central Europe, something you might find helpful: the altitudinal V-BAM for Central Europe, bounded by the 30th parallel north, the 60th parallel north, the 30th meridian east, and the Prime Meridian. Thanks to QGIS's raster calculator, maps like these are actually pretty easy for me to generate, so if you want one for another part of the world please don't hesitate to ask.
However, big huge NB: these altitude maps do not contain any information regarding any inland bodies of water. So lakes, rivers, and inland seas with no connection to the ocean will still need to be added.
Anyway, enjoy!