Hi,
I have some experience with laser printers, though more with Windows than Linux.
B/W laser printing has worked out well for me, in terms of economy, function, and convenience.
You definitely ought to get a true PostScript printer for Linux. I recommend using one with a built in ethernet print server, as it is handy in general. As suggested above, have a look for Linux printing guides (LinuxPrinting.org?).
I have used an Epson EPL5900L b/w laser printer with Ubuntu at home, and this is a bit painful. A verey manual installation. Also, the Windows native drivers are poor. I don't like Epson printers in general.
I use an HP multifunction printer at work, under Windows, and am not impressed. The drivers are rubbish, and the printer has crashed several times in the last three weeks.
In general, I think multi function printers are more trouble than dedicated b/w laser, particularly with network print servers.
I have had good experiences with Kyocera, though have not used them under Linux. Have found them to be fast and reliable, and at least their Windows drivers are good. They are not the cheapest around.
I would be cautious of buying second hand laser printers, as the drums (or other photo-electrics) can wear out, and that is the heart of the printer mechanics. You should get a usage/service history of a second hand laser, and examine a sample of the printer output. Bad photo-electrics will give poor toner transfer to the paper.
Hope this helps.
Oli
