http://images.dakkadakka.com/gallery/2015/2/25/690099_md-.jpg

I've made my own custom debris, but cannot find "debris bases" anywhere online. Are these custom or does a site in Europe sell these?

I know www.space-rocks.co.uk do various asteroids and debris, so I'd start by checking them out.

Those look like cor-sec engineering flight pegs. Might check there.

I know there is someone who does debris shaped bases. Not sure if they are based in Europe.

well, we do acrylic obstacles (debris and asteroids) beside other stuff, I don't see much of a problem on our side in cutting a hole into them for a peg... ;-)

http://www.miracle-versand.de/Acryl/Marker-Token-fuer-X-Wing-Weltraumschrott-Debris.html

Cog'o'two does acrylic asteroids and debris, though they don't have the stands if thats specifically what your after:

http://www.cogotwo.com/x-wing-compatible