Sorry you're having problems with the Airport printing option. It's such a handy feature!
Dell printers will not work at all and as you've probably found only a few Lexmark printers do.
HP has a list of compatible printers; URL is below.
If you don't mind an alternative suggestion, perhaps a Canon inkjet printer? We have three different Canon printers at home (long story) and despite one of them being almost 5 years old, they all work with our Airport.
The MP470 (which we have) can be found for $99 or less and I've read good things about the budget MP210, which is now $69. With the PG40 black ink cartridge ($19.95), I get about 200-220 PDF pages printed.
Please note that you cannot use any printer utility (ink level, cleaning, alignment, programmed silent mode) through the Airport, it has to be connected via cable.
I would also suggest renaming the Bonjour printer so it's not confusing when you plug in a wired one. For example, "Airport iP90" instead of "Canon iP90."
[I have nothing against laser printers but having worked in electronic sales until last summer, I found that any sub-$299 models curl 20# paper too much.]