Not looking to stoke a flame war, but Creative really does NOT make good products.
Their sound cards are sub par at best, their drivers and OS support are terrible and they are overpriced.
The last pair of Creative speakers I owned where junk and I hear the new ones are not much better.
Stick with Auzentech, ASUS or HT|Omega for the sound card and someone else for the speakers.
My staple sound card recommendation is either the ASUS
Xonar DX (PCIe) or
Xonar D1 (PCI).
Both have excellent sound quality that NONE of Creative's cards can best (not even their $280
X-Fi Eliete Pro)...
At $90 they are not priced over the top either.
As for speakers, I almost always use headphones so I am not necessarily an expert here.
I have heard mixed things about the
Z-5500.
I hear that it has lots of bass (perhaps even to much) and, depending on who you ask, it is either reasonably detailed or really muddy, usually described as somewhat lacking in the mid range.
I personally use the much cheaper
Logitech X-540 when I have guests and find them to be reasonably detailed with pretty good (if somewhat shallow) bass.
Still 1000x better than my old Creative 5.1 setup...
I would recommend staying away from Bose.
Their products are really over priced for what they offer, which is not really accurate or quality sound.
I have also not seen anything good come from Altec Lansing for quite some time.
Klipsch, Harman Kardon, M-Audio and Logitech are the brands I hear tossed around most with good PC speakers.