Here is my issue
I like listening to music, mostly old school rock

I have Altec Lansing FX 6021 speakers running on an integrated Realtek sound card.

I was thinking of upgrading my listening experience. Since the worst part is the integrated sound card, I was thinking of getting a new one, since I am not leaning to perfection, nor do I want to spend a fortune I was thinking that the
Asus Xonar DX would be a good choice (priced at 60 eur or so), I understand I do not need a 5.1 or 7.1 card but it seems all the stereo cards are for pros and cost like 3x more (ASUS
Xonar Essence STX or M-Audio or EMU cards) and I do not want to make music I just want to listen to it

maybe the M-Audio Audiophile 2496 is better for what I have in mind?
Also I am using Windows 7 64 bit, I rly don't want to have any driver hassle, when the card is installed I want it to work

Can u recommend
something better in the 50-100 eur price range ( 70-140 usd)

secondly

when I get the card and get a improvement in listening experience I might go for a pair of new speakers, since I think the speakers I currently own are top what PC speakers can offer, I thought of getting studio monitors.
Now u might say, why studio monitors? do u have a studio? Well no, I was thinking of monitors simply coz they are mostly made active speakers (don't need an amp which costs money), and if they are used in the studio for production of a song, they should be enough for me.
For the new speakers I would prob spend up to 400 usd.
Several studio monitors fit in this budget
KRK RP6 G2
M-Audio Studiophile BX5a Deluxe

Do u think I shouldn't go for studio monitors? Why?
What set up do u recommend? Why?
If not monitors, what?

Do u think the Xonar DX would be capable of supporting these?

Thx in advance for any help u might provide