I was browsing my local Computer store promo and ran into this external monitor. Not a lot of reviews out for it yet but seems like a good balance on size and portability vs price. Only thing it was no internal battery but since it takes 5V 1.2A most smartphone/tablet style battery pack can power this. I am still trying to get confirmation on compatibility with 24/50fps but maybe someone else already tried? specifically with the Panasonic GH4?

http://www.gechic.com/product_help_en.asp?s=15

http://www.bhphotovideo.com/c/product/1057704-REG/gechic_corporation_1002_10_1_ips_lcd_touch.html

http://www.amazon.com/On-Lap-1002-Portable-Monitor-Touchscreen/dp/B00J9XCFOS

What I like:

• $240 ish
• IPS panel with 170 viewing angle (horizontal and vertical)
• takes 5V 1.2A input
• comes with cover/stand/VESA mount all in one accessory

Complete marketing overview:

Whether viewing photos directly from your camera, playing games, or adding another monitor to your laptop the On-Lap 1002 10.1" Widescreen LED Backlit IPS Touch Monitor from GeChic offers a wide variety of viewing and connectivity options. The display also features 10-point multi-touch display along with intuitive control options such as QuickScroll, handwriting, hand drawing, and more.

The On-Lap 1002 features an IPS panel with 170° horizontal and vertical viewing angles allowing the display to be seen from nearly any angle. The 1280 x 800 resolution and 800:1 contrast ratio ensure whatever is being viewed on the 10" screen will be seen clearly.

This versatile display solution isn't just for plugging into your laptop to be used as a secondary display; it has other uses as well. The multi-touch display allows for multi-player gaming, you can position the display in either portrait or landscape modes for use as a digital signage display, and you can even connect your camera directly to the display via an HDMI cable to get a better look at your latest photos.

Multi-Touch, Ten Fingers Together

The On-Lap 1002 Touch Monitor uses capacitive touch technology, supports ten finger multi-touch recognition, and comes compatible with Windows 8's multitasking gestures. Select, expand, QuickScroll, handwriting, and hand drawing can all be achieved. In addition to being used as a main monitor with touch functionality, this monitor can also become a second external monitor.

Light and Slim

The On-Lap 1002 is designed for portability as it weighs in at 1.1 lb (505 g) and features 0.4" (1 cm) slim body. The On-Lap 1002 also comes with a flat-back design, allowing it to be placed horizontally on-table.

Transform Your PC into a Tablet

The On-Lap 1002 can be used as a laptop or desktop's second monitor to provide a tablet-like user experience. Additionally, if that laptop or desktop is running Windows 8 and you don't have a touch monitor or screen, the On-Lap 1002 can allow you to fully interact with all of the included touchscreen features.

IPS Wide-Viewing-Angle Panel

The On-Lap 1002 comes equipped with high quality IPS panel, providing 170 degrees horizontal and 170 degrees vertical viewing angles. Additionally, the 1280 x 800 resolution and 800:1 contrast ratio generate a crisp, clean picture.