Agree with the icom. Agree with at least having a T connector to the present COM antenna installed, so you get the range. I donīt know if they still make the King with a built in GPS......it was TERRIBLE! All the icoms I have had (have sold them on when I delivered aircraft) were excellent.
I used my own all the time for ATIS, picking up clearances etc without having to use aircraft battery or even having to get in, put the headset on etc.
Even being in the hotel near the airport and listening to the ATIS was sort of useful at times. I did call the tower once from the hotel to delay a flight plan and it REALLY freaked them out, as they had a DF on their receiver and it was indicating a completely wrong direction from where my aircraft was parked....(oops)
Also useful if you have a club or company freq to check arrival times, alter parking positions "The aircraft is going out again, please park up at the fuel station" sort of thing.