for you ethernet card you might want to try this site out
http://www.scyld.com/
or check out the homepage of you manufacturer of the card and they might use the same type of chipset as other supported cards and one of many other drivers might work within linux.
for the lexmark, you might want to check out their homepage, a lot of their printers are like winmodems and need software to work, i only really know of two of their printers working under linux and they are the ones who created the drivers for it to actually work.