Ive been installing stuff myself for a while now, i did my vehicle back in may.
It took about 8 hours over the course of 3 days to do everything, i used sheet metal to make a brace so the headliner didnt have to handle all the wieght of the flip downs. Very easy to do if you take your time. PM me if you want bigger pictures.
Before comments roll in no i dont watch tv while i drive, i dont have kids i did this for car shows etc. I take alot of road trips with friends and these where the best money i have spent on my 13 hour drive to disney. Was about a grand for all the monitors, the DDIN dvd player, the video source amp, and all the hardware. Got quotes ranging from 800-1200 just for install and 2000-3000 for install with parts.