Kirk Photo — makes both a bottom bracket and L-bracket for the camera.
ProMediaGear — PLNZ9 L-Bracket with SS2 strap port. US$199.95
Really Right Stuff — makes both a bottom plate and a modular L-bracket for the camera.
SmallRig 3714 L-bracket — L portion is removable, and can be positioned away from the doors. US$69.
SmallRig 3195 Arca Swiss Camera Cage — lean camera cage, with handle option. US$99, US$50 for handle.