Indeed there was a nice Moria port to AmigaOS:
http://www.lysator.liu.se/tolkien-games/entry/dungeons-moria.html
it features graphic tiles and the standard campaign ( e.g. slay the near invincible Balrog on level100+ ). I haven't tried it myselves on Wiz so its playability is unknown. However was quite playable on Amigas with a dedicated numeric keypad (e.g. *not* the A500/A600). Biggest issues would be the screen scale which hampers the text-rendering. Ideally you would turn off any screen scaling even by sacrificing some surface parts.