Step 4: The Screen
Many other screens can be used. If you do not decide to get a PS1 screen, make sure the one you do get can accept composite input, and get one that runs under 12v, or picking out batteries will be very difficult. Many pocket TV screens can be used, like the Casio pocket screens.
Other good screens are as follows:
Hipgear/Intec Screenpad: 1.8", good quality. Runs on 5-12v. Here are pinouts and other info. Has audio amp. Find them at garage sales or possible eBay.
AEIComp Screens: 1.8" to 17". Expensive, but great quality. Here is a guide to making it smaller and where to attach video. No built-in audio amp. Takes 5-12v.
DealExtreme Screens: 2.5", 3", and 3.5". Good quality, cheapish. Here is a guide for the 2.5" one. All take 7.5-12v.
Casio EV-680: Good quality, takes 5-6v. Hacking Information. Look on eBay for these, or maybe garage sales. Other Casio TV's are good, as well.