Buying Expo Have a few questions

[Jmack]

First off Hello and happy new year! Now on with the business. I have found a 2004 Expo EB premium with 113k for 10,500. Is this a good deal?? The truck is beautiful in and out no rust on the tailgate or hood the engine sounds strong and it drives wonderfully. If I buy it I want to swap out the factory nav for a aftermarket unit but im not sure if I can retain the overhead dvd and other options. Lastly what should I look out for in the model year I really would hate to pick up a lemon !!! lol