Ask HN: Most Hackable Android Tablet?

I want to build a touchscreen control panel for a project I'm working on, and it seems like the best choice here is to build the UI in a web app or mobile app and use a tablet to host the touchscreen interface.

Does anyone have a recommendation for a tablet that works well in "kiosk mode"? I'm also hoping to control screen brightness, volume, and other system things like that from the app, and it would also be nice if I could have it boot directly into the app when the tablet starts up.

Is there anything out there today that provides a full android build? I don't mind closed source drivers, but it would be nice to be able to build and flash a custom ROM.

Wireless charging would be a bonus, but not a hard requirement.