Just bought the Standard Horizon GX 1700. Manual indicates Flush mount cutout: 5.4” W x 2.8” H x 2.6” D.
http://www.standardhorizon.com/indexVS. ... Archived=0
I went with this radio because of the Internal GPS. Why? We decided against getting a dedicated chartplotter, or the beautiful Raymarine e7 unit, and opted instead to use an iPad running iNavX for navigation. My father has had good experiences using the ipad as back-up for his plane, and I hear all good things on the cruising list serves I monitor. Downside of using the ipad is that i have no direct gps feed to link to a DSC capable radio - this covers that. Probably overkill, but whatever, we needed a new radio.
BUT
Decided against mounting on the gauge panel. I thought it might be a little awkward, sort of behind the steering wheel with the cord hanging down, and instead decided to mount a new Garmin echo 550c fishfinder there (it's 6" x 5.9" x 1.8"). I am going to put the radio either in the box up top, hanging from bottom of dash, or in the starboard side panel at the helm. Haven't decided, heading to the boat this weekend to figure it out. getting a new panel and gauges from Vector LED.