I have Gutenprint installed and I've seen Canon ip4000 listed when I snoop through the available ppd's. That does not quite work that well with my ip8500 (networked printer just for the fun of it). It does work great with my Epson printer though.
Another option that you will have to Pay for is Turboprint (http://www.turboprint.info/). I've heard that they have excellent support for many more printers. I don't see the need to pay for a driver in addition to having paid for my printer though, but that's just me. Otherwise, you'd probably have to purchase another printer that is supported by Linux.
Gutenprint 5.0
Have you tried Gutenprint? I know that it does not support every printer but it does support many. http://gutenprint.sourceforge.net
Here's a link to a list of supported printers:
http://gutenprint.sourceforge.net/p_Supported_Printers.php3
I have Gutenprint installed and I've seen Canon ip4000 listed when I snoop through the available ppd's. That does not quite work that well with my ip8500 (networked printer just for the fun of it). It does work great with my Epson printer though.
Another option that you will have to Pay for is Turboprint (http://www.turboprint.info/). I've heard that they have excellent support for many more printers. I don't see the need to pay for a driver in addition to having paid for my printer though, but that's just me. Otherwise, you'd probably have to purchase another printer that is supported by Linux.