AppleTalk must be turned on via the method they are connecting with -- like Ethernet -- and AppleTalk can only be active on one service at a time.
10.5 will network to 9.2 via Ethernet. It's either not set up correctly in hardware or software, or both. See the Guide.
Is there any particular reason you'd like to stick to Linux?
As for the "older version of OS X" for compatibility -- see the Guide, with The Chart. For running an AFP file server under Classic under OS X, couldn't tell you. Interesting question though, but I don't have any machines that run Classic so I couldn't tell you...Well, right I don't. 10.4 was the last to support Classic so you could try connecting to something old like a System 7.0.1 Mac with MacTCP -- which would be incompatible with "raw" 10.4 Tiger.