"but I'm really confused with what I can and cannot get so that it pairs with the sound card"
Nothing to worry about. Any headset (any PC headset, that is. Audio headphones use a phono plug incompatible with PC sound inetrfaces) can interface with this adapter. A 5.1 Headset, like the Medusa I own, will have three plugs for Front, Rear, and Center/SubWoofer. You will set the sound adapter using its Audio management console to 5.1 Speakers. This will set the correct output in three of the jacks on the adapter. Simply plug the three plugs into the appropriate jacks. The other adapter jacks will be unused except for the microphone jack, where obviously you plug in the microphone plug.
The point is that the sound adapter jacks in use depend on which speaker mode you use. In Stereo (e.g. simple stereo speaker/headphone) you will use one jack, for example, while in 5.1 you use three jacks. In 7.1 speaker mode you will use all of the jacks there. Surround headsets come in 5.1 mode. I've never heard of a 6.1 or 7.1 headset. You set the speaker mode of the adapter via an Audio Management console of some sort that gets installed with the driver.