Hello, there are printers available, especially ones that use Postscript, is it Laser or Inkjet you're looking for?
Highest you can go is 10.5.8
* Mac computer with an Intel, PowerPC G5, or PowerPC G4 (867MHz or faster) processor
minimum system requirements
* 512MB of memory (I say 1.5GB for PPC at least, 2-3GB minimum for IntelMacs)
* DVD drive for installation
* 9GB of available disk space (I say 30GB at least)
Classic/OS9 Apps no longer supported.
May be available from Apple again...
Trouble is Apple no longer sells it, check eBay & such for the Retail version, not the Gray Discs...
There are workarounds if the 867MHz CPU is the only hangup...
List of Applications Not Compatible with Leopard...
You may be able to upgrade to Leopard but that is as far as your G4 could go:
Leopard system requirements:
As Leopard is no longer sold by Apple you will have to look in Amazon or eBay for a black retail install disk. Expect to pay up to $200.