We've got a list here

Comics R Us has vintage and reissue TFs and other 80s toys like MOTU, and is probably the largest comic store, but at a cost premium. Classic Comics is smaller, only comics, but many of us are more loyal to them. Minotaur is the largest store, and has a large range of comic collections, but their back issues are non-existant, and lots of other popculture stuff. But you can also visit all three in an hour or so since they are close by in the CBD.

Trading cards? Hmm. Most of the comic shops don't deal in them. Alternate Worlds did, but there main store closed down and I'm not sure what their new store is like (and it's in the outer suburbs). I think there are some specialty shops still around but not many survived the 90s boom/crash. There's always plenty of card sellers at collector fairs so some of them must have shopfronts but others might know more.