If it works in Windows, it will work in DOSBox.
I wouldn't recommend any sound card for DOSBox: DOS sound usually was not high fidelity, so any sound quality would be wasted. Maybe, you are looking for a sound card with low CPU use, but...
In any case, I've got an Asus Xonar DS. It works in Windows XP, 7 and Linux, and it si well rounded. Maybe it is not the best sounding card, or the fastest, but for the price is a very good option.
Avoid at all costs Creative sound cards; because their compatibility with newer operating systems is always poor. SB Live! and Audigy lost some capabilities in Windows Vista (capabilities that were present in Windows XP drivers), and I doubt that they'll get drivers for Windows 8.
I have traveled across the universe and through the years to find Her.
Sometimes going all the way is just a start...
I'm selling some stuff!