Try to find transflective lcds. They reflect external light: more light, more bright images.
The problem is, most trasflactive LCDs are b/w and small. Few manufacturers have color VGA-size products: for example, lg-philips makes LC121S1. Someone told me that also NEC has one.
Of course, you will need to add LVDS interface, inverter, and a box.
Of course, you will need to add LVDS interface, inverter, and a box.