So far the to do list includes:
Stereo: New DVD head unit. Replace door speakers with 6.5" rounds (got adapters but might require some modding by looks of things...) 4 speakers in rear (in storage area above cab and 2 on bulkhead) on a switcher, on their own amp, (will explain in a bit...) 22" TV in rear, some sort of games console under rear seats.
Lighting: Some LED strips on ceiling in rear.
Power: Fuse box from one of the 3 60a user points running x4 8v USB sockets and other AV/Lighting in rear. Inverter for 230v AC.
And whatever else I think of along the way
So far just swapped out the stock head unit for a sony DVD unit and installed the LED strips in. Plan is to have the rear 4 speakers on a switcher that let's you swap between the Playstation dvd sound and the stereo sound. Then have the output from the switcher run to a potentiometer in one of the slots on the dash and run back to the amp. That way I can have independent control over say a movie playing in the back and radio in the front.
Here's a pic of the HU installed. Bought a big old instal kit and literally just needed the fascia and what came with the HU in the end !