I have been using Avmap EKP IV for a while and apart from rather clunky PC interface
using C-MAP's "PC Planner" and "suspect" battery life (doesn't really matter, since I am running it from the main battery anyway) it is great.
Mine is panel mounted, using Air Gizmo mount.
Dead easy to use (once you get used to quirky menu
)
and (stiil) the largest screen.
Chris