Need help with Microphone

Hello,

     I am finishing up a build and have decided to get a soundcard, I am looking at the asus xonar DX, or the creative Z, someone said that the stx is great, but is it worth an extra $80 over the z or the dx. I have beyerdynamic dt770 pros to use with them.  Thanks

Edit:need a mic

Blue snowball vs blue yeti? 

Yes, if you have DT770's a Xonar ST would would be worth it. Go with an ST over an STX I've listened to both of them personaly the ST honestly does sound a lot better.

Thx

No driver issues on the st for win 7 right?

And for the dt770 pros, is it worth it to get a blue yetti mic later or, or should I get a blue snowball or whatever now. Blue yeti later or snowball now guys?