I have the same year and set up as you. 75k miles and the valve body was bad.
Sent my valve body out to these guys -
Home Page
About $650 as I recall?
Johnny is a good guy. He will swap yours out, but as he and I agreed, it is better to rework what is currently in your car.
I purchased the filter, gasket and fluid from Blauparts.com.
You probably do not need to do this, Mobil One Synthetic trans fluid. It will take about 5-6 liters as I recall. You can likely reuse the filter and pan gasket?
I also made/used the blow gun extension from my cheap Advance Auto blow gun and a cheap fluid pump to fill trans from the pan drain.
This is not a hard job, BUT, you NEED to take picture and make some drawings about the wiring and brackets. Also you need to be VERY careful with the wiring connectors so you do not break anything. Once you figure it out, not bad, took a while to figure out the first on.
Valve body is bigger and heavier than you would think, not too heavy, but be ready as it is VERY deep/tall.
Also before you button everything up (no trans pan), turn on ignition and make sure you have EVERYTHING electrically connected back up. I think there are 12 connectors. If you have anything wrong you will likely get trouble codes and the shift indicator will go into error mode. Ask me how I know!!