What sound card?

Hi all.

I'm puzzled.
I've spent some time now searching for a basic soundcard that would meet
these specs, to no avail. What would you then recommend?

My specs:
PCI 2.0 soundcard (not 2.1, 5.1 nor 7.1) - does any manufacturer ever
make those anymore?
XP and Vista compatible - will be used on a dual boot system
Not too CPU-load-demanding - at least much better than any integrated
sound chip
Will collaborate with Mackie Onyx Firewire soundcard - Mackie ASIO
drivers are used for pro audio apps, and the basic soundcard will be
used for multimedia and game apps
Sound not too crappy.

Any advice welcome. You could even mention chip names, which will help
me find different cards using them.

Thanks a lot.
Sam.