Nothing wrong with 16/44. It's what cd format is based on. Properly recorded this can sound really good. You'd need much better speakers than ms20, think thousands of dollars to tell the difference of higher dynamics which 24 bit recording could deliver.
Now, this said on board pc dac are mostly crap in fact, but for totally different reasons. The problem is inside pc there is a lot of interference which dacs tend to pick up easily. Like you move a mouse or hard drive read, if you hear unexpected sounds - this means that you have rfi issues.
Going with external dac is the easiest answer (hard way would be to fix these issues, but it require complex design and specialty parts)
Going with external dac on Behringer ms20 speakers should be fine. Yoy might still have ground loop issues, but thats different conversation.
I must point out that i used to own ms16 speakers. They were OK for money, but honestly don't expect them to be suitable for real music studio recording. They perfectly fine as good pc speakers.
