Seaview, now owned by PYI, has added dual electronics mounts to their product line.

The Seaview DM3 and DM4 are designed to accommodate installations with limited clearance ahead of the mount.  The DM3 supports a satellite antenna and radome, while the DM4 model supports a satellite antenna and open array radar.

This is the DM4 with Seaview light bar.  Sorry about the NEW button - it's the only pic I had.

The Seaview DM3 and DM4 feature modular top mounts at both mounting positions offering flexibility for radar and satellite dome installation options.  DM3 and DM4 mounts can be used with a variety of different adaptor plates to accommodate boaters’ exact installation requirements. 

They are constructed from primed and powder-coated marine-grade aluminum and are available in two models for closed radome and open array radar.  The dual mounts accommodate 14-inch to 18-inch satellite domes. Both the DM3 and DM4 have a base mounting plate that measure 10x10-inches with the radar mount elevated 6.5-inches high and satellite plate 27.88-inches high. The total width between the mount bases is 43.74-inches wide to ensure separation of signals and eliminate interference.

Both the Seaview DM3 and DM4 carry a three year warranty and are available for $1,300.