I am using OS 10.3.3 and am experiencing very slow printing (about a line every 3-5 seconds). I have updated gimp-print to 4.2.6 and get the same results with an Epson Stylus Photo 2000P.
It does this in every program.
Yes, if you do a custom install of Panther, the drivers for the 2000P are included with Epson printer drivers 2, which is on disk 3, unless your installer is on a DVD.