7" Native HD Component monitor, $400
 

Xenarc 700YV: $320
Mayflash VGA001 Component to VGA converter: $50
DC-DC SEPIC regulator: $20

With my DIY hands, I am up for saving a couple hundred bucks. For others the trouble may not be worth it.

I started with my dremel, cutting a hole in the back of the case of the Xenarc. I cut a small project box to fit flush against the hole, and then used putty to attach and shape the edges. Drilled holes for the Mayflash component in, and wired up the VGA output from the converter to the internal pins on the Xenarc monitor. Then wired up the power from the 12v input of the monitor through the DC regulator to the converter's DC input. Attached the mayflash board to the enclosure with some glue and JB weld, and closed it up.

It saves the bulk of having an extra battery pack, and two extra wires, as well as having to buy the extra four AA batteries that wear out after 2 hours; I have two big 4500mAh 12v bricks I use for the monitor, so the extra power draw is not a concern.

If anyone in the Xenarc+Mayflash situation would like me to, I can build small doo-hickies that take 12v in, and split it to 12v and 6v for the mayflash and xenarc. They are not resistive voltage dividers so there is about 80% power efficiency in the conversion.