A Texas company which is building some nice camera accessories in Europe was showing magic arms and camera cages at NAB New York.
Mottus Corp articulating arms have knuckles with rubber inserts, inspired by scuba gear, which lock very solidly and easily. The arms have 1/4-20 and 3/8 holes and studs along the length of the arms, so you can attach anything you want to them.
The arms are rigid enough that you can use them as handles for smaller camera rigs. The end studs on the arms don’t move – they rotate only in the middle – so the range of movement is less than most magic arms. But you can get various attachments to customize your connections. These would be good for mounting recorders or 1st AC monitors to your cameras, but probably would not be good for an EVF.
Mottus is also selling a range of lightweight one-piece cages for popular mirrorless cameras.
An 11″ articulating arm is $149 US, while an 8″ one is $120. Their bare cages are in the neighborhood of $200 US for Blackmagic Micro Cinema, Sony and Panasonic mirrorless cameras.