I'd suggest you look into using Chromecast as an alternative to HDMI and a wireless HDMI transmitter. It would require that you have WiFi available at the location you're shooting, but would allow you to use just about any tablet. I just tested it with my Nexus 7 (2013) running Android 5.0.2 and it worked great. Just turned the camera on and cast the screen to my flat screen TV. If you're interested, scroll through the Android Tablet News Depot section of the forum. There are several articles about Chromecast there.