There are a few out that I know of, one box wonders. The Techincs AC series, probably less than $200, but I will tell you my favorite, is the McIntosh MDS-4. Now this this WILL cost anywhere from $900 (if lucky) to $1,200, but this unit does EVERYTHING the MX-132 does as a processor! The best part though, prologic, DD, DTS, but it comes with its OWN remote! There is no switching involved, but for a few bucks more, buy the MVS-2/3 and it is a McIntosh swither!
NOW, this set up is exactly that of the MX-132 ($7,000 list) shy of the tuner! There are professionals that feel this set actually sounds better for films since there is less procssing to work through. Yeah, not sure about that, as I doubt anyone or any system would be able to notice small chages for surround sound like that!
Other than that, MSB Technology might be able to add DTS for $$$, probably less than $500 (guess) to your DDP-2.
Keep us informed with the route you take.