Well, all your equipment can handle both DTS & Dolby Digital. DTS *is* higher quality sound, but some people can't tell the difference. There's a whole controversy over it.

The one thing to check is that most DTS discs do not offer any special features due to the added space occupied by the audio stream. You get the movie and that's about it. Plus, they're more expensive. It's up to you, but it's not THAT much better.