I tried my 5.8GHz Fatshark 250mWatt with Sony 600TVL and that worked very well with my 32channel diversity screen (cheap Chinese no brand), as well as goggles. I made it as removable payload because I don't expect to use it much. The image is basically OK..ish but the movements of the inspire make it a distracting experience, specially with a lot of crosswind, although you see what your bird actually does, which can be a good thing at times.
I think having the map on the PS screen while the gimbal is operated by a separate person looks like the best option. No distraction while you check your telemetry and position, and you have to keep line of sight anyhow.