I don't believe that Panasonic has any DVD players with better DACs than the RP-82; it's just not a priority. I don't think any of there current models have particularly good video performance either, as they no longer use the Faroudja chip that gave such stellar performance.
If you want more detailed discussion, head over to www.hometheaterforum.com, and look under the audio/video sources. If you are looking to spend around $300, it shouldn't be hard to find a Denon 1600 DVD player, which has the video performance of the RP-82, plus much improved audio DACs. I think this player also does DVD-A.
If you want to spend more money and get a solid universal player, I think the Denon 2200 or 2900 is the best choice; they use Burr Brown DACs which are supposedly very good. They strike a balance between features, audio/video quality, and reasonable price for something that may be obsolete in a few years (different audio formats and digital connectors).
-Cooper
