AN2,
Given the EIR holder is going to fly in the airway system, he needs BRNAV. Which either means e is hard core and has an FM immune KNS80 or he will have something like a G430 which gives pretty much all the approach aids you would want. You then just have left the question of needing a DME and/or ADF for enroute (which I think is going away or has gone away ).