Hi EB58,
I understand you're working with a Mac using 10.4 for the operating system and are wanting to know which HP printer is compatible with it. I will certainly do my best to assist you in this.
The only printer that I can find that would still be available in some places is the Officejet 4500. It is an all in one, so it should be able to do most things you'd want it to. If you're not able to find this printer or are looking for some different options, you can always call HP Tech Support for your area and inquiring with them what other suggestions may be available.
Hope this helps, have a great day!!