I would think both exception No. 1 and No. 2 would apply.
210.8 Ground-Fault Circuit-Interrupter Protection for Personnel.
(A) Dwelling Units.
(5) Unfinished basements
Exception No. 1: Receptacles that are not readily accessible.
Exception No. 2: A single receptacle or a duplex receptacle for two appliances located within dedicated space for each appliance that, in normal use, is not easily moved from one place to another and that is cord-and-plug connected in accordance with 400.7(A)(6), (A)(7), or (A)(8)
Isolated ground, isolated from what in a typical residence?
If you run it in NM from a main panel it will be isolated, as long as you don't mount the box to a water pipe.
But if the customer thinks it is better what can you do.