remote file sharing

Hi,

I'd like to be able to remotely access a g5 mac with 10.4.11 on it, and browse and download files from it. I have configured the DDNS service on my router, and it's working fine, when the wan IP chage, this change is seen on the DDNS account page of the provider. I also have enabled on the mac the personal file sharing, the windows file sharing, the remote login and the ftp access. I really don't care which protocol I will have to use, but, for the sake of simplicity, let's say I want to connect through ftp. So the ftp access as said is enabled on the mac, then I know that fpt uses port 21 and 22, right? Should I port forward those ports to the ip of the mac? But, should I use a different wan port, like 6000, and use the 21 on the lan side? would this work? Or should I choose a different protocol all toghether?

Please help.

Thank you.