OK, it's not a concept. I built it, it's nearly ready to go.
However, until it works, I will call it a concept.
Fieldview 777 screen, Boscam 5.8GHz VRx with ImmersionRC circular polarised antenna.
3S 1000mAh battery not shown, but will hang underneath.
It's a bit heavy, but I'm sure I can hold it, especially if I sit on the ground or on a chair. Switches might be a bit hard to get to, but to switch modes shouldn't be a problem.
I used a modded plywood FPV holder because it didn't fit the dx6i anyway. So chopped a bunch of wood off and screwed it to the back of the case.
The Tx antenna only fits sideways which shouldn't be a problem, but I intend to replace the antenna with a coax for installation of a 2.4gHz WLAN amplifier which would then be mounted on a pole (a stick, not a Polish person).