install help w/ large video in 4runner

Sounds like a tough install. That's a lot of weight to hang from your headliner. You might be better flush mounting a 7 inch widescreen in the dash where your factory head unit and pocket are located.  You could re-locate your new head unit under the change/ ash tray. That would allow you to view the screen as well.  If you still wanted to mount the 14 incher in the back, I would recommend screwing in some support beams to any solid metal between your headling and ceiling.  The more surface area that you can distribute the weight to, the better. Also remember that you need to stay clear of the sliding door for the sunroof. This can be tricky, and you'll probably have to play with it a little bit.  As far as the cosmetics, I would suggest losing the existing stand that the monitor is attached to and using that bolt pattern to fabricate a new bracket on which you could use to create some shape to. Once you've created a frame for the screen, use body filler to flush mount the monitor to make it look as factory as possible. Don't forget though, the more filler and metal you use, the more weight it will add to the structure. Finally, wrap the finished piece in matching vinyl or carpet or whatever you choose.  Like I said, this sounds like it could be a very challenging install.  I really hope you pay your installer well! Shower him with money!

Good Luck!