New headset + Sound Card? Help needed

Hey guys. Ive recently got a pair of ASTRO A40's with the mixamp. These things personally are terrible. Ive been doing some research and Ive come across two great looking (and with good reviews) headsets. http://www.newegg.com/Product/Product.aspx?Item=N82E16826106685 http://www.newegg.com/Product/Product.aspx?Item=N82E16826106686 The Sennheiser Game One (Link one, Open sound headset) and the Sennheiser Game Zero (Link two, Closed ear headset) only problem is you need a sound card to really get your money and %100 from these guys. The open ear headset has an input impedence of 50ohms and the closed has one of 150ohms. I want to get the closed ear headset, with the 150 ohm impedence, idk how all this audio shit works, but ive found this card http://www.newegg.com/Product/Product.aspx?Item=N82E16829132052&cm_re=ASUS_Xonar_Dgx-_-29-132-052-_-Product I was wondering if someone could tell me if these would work well with one another. For more info this is my motherboard I have, http://www.newegg.com/Product/Product.aspx?Item=9SIA25V1YY2261&cm_re=ASUS_P8Z7_PRO-_-12K-00HP-00078-_-Product. I wont be ordering these online, more rather going to my local microcenter and having them price match. Thanks for any help.

EDIT: I actually dont even know if thats my mother board, I must sound stupid. There are so many models of the ASUS P8Z77-V, Ive looked at my receipt and also my mobo box, none of which gave me the exact P8Z77-V model, like I said there are many...and I cant seem to figure out which one I have....

that sound card probably won't do an awful lot for you. your best bet would be an external amplifier, so you could probably get something cheap like a Topping NX1, or Creative Soundblaster E1 (uses the same chip as the fiio E07k, works as a dac too).