Multiple Monitors

Hello all, I need some advice on how to power all these monitors. 

 Two 6.4inch Headrest - Under 7w power consumption each.  I already have these installed. but one seems to flicker and the top left corner of the screen gets wavy like not enough power.

two(2) - 8 inch Visor monitors 9.5 w power consumption

One(1) 5 Inch Rearview with backup camara - This will automatically flip to the backup camara when i put the car   in Reverse. 9.5w power consumption

One Indash 7 inch Flip out one din Player - that will also replace my existing cd player so am not really worried about power here.

I currently have one main wire from the battery and have my remote start /alarm and tons of relays attach to it so nothing runs untill the car starts.  I also have a power inverter hooked up.  For the monitors, i currently have a power wire from that same main line comming from the battery with a relay that supply power to the monitors and dvd player when the car starts, otherwise there is no power.

Is it better to get a distribution block for this setup or can all these screens be powered from a really big gauge wire on a relay of course.  Do i need to have a relay for each monitor or is it okay to run them from one wire with one relay to control the power?

I also have a 6 output video amp installed and intend to be able to watch a different program on the visors than whats playing on the headrest monitors.

Any and all imput or suggestion for this setup would be much appreciated, thanks.