I use a wired connection for all streaming from my NAS to my media player and don't have any issues. If you don't have a possibility for wired, you can look at ethernet over your power lines as an alternate solution. I've used that with success as well.
I went the NAS route to store all my media files (photos, music, DVDs in ISO format). This way any device or computer in the house can access the files. Additionally, I don't have to have a computer up and running every time I want to watch a movie or listen to music. I used to have an external drive hooked up to my media player before I got the NAS. I liked that as it provided fast access and there are no buffering issues using USB. However, I got sick of unplugging the drive, copying new files to it from the computer, hooking it back up again and so on. With the NAS, I just log onto my computer, rip my music from a CD or movie from a DVD and put it on the NAS and any device can see it (with security of course). I do the same with camera pictures - a feature my wife likes so she can have access to them from any computer.