I think it depends on which engine you're using in amarok for playback.
you could try the xine engine, which should make use of the win32 codecs you've already installed, otherwise, if you're using gstreamer, i think you'll have to look up the gstreamer aac / m4a plugin. then you should be ok.
not sure where you'll find a pre-packaged version of the latest amarok - packman is probably your best bet for suse, so i'd keep an eye on that. or you could have a go at compiling it yourself - but it is quite a complex application with lots of dependencies; if you follow the instructions though, it's not too bad. i'd say have a go - i'm running 1.3 on the latest ubuntu and it's brilliant.. particularly the wiki artist information.