Rogerdn,
Isolated grounds?
If the gentleman was speaking of NEC approved branch circuit isolated equipment grounds, as used in commercial or hospital occupancies, then I assume he is talking about the use of isolated grounding type receptacles with insulated equipment grounding conductors.
Regardless, the equipment grounding conductor still has to terminate in the same panel the branch circuit is fed from.
Unless you are going to have the electrician install your two dedicated branch circuits in metallic conduit I see no need for using isolated grounding type receptacles.
If your electrician can use and install NM-B sheathed cable, (Romex is just one manufacture of NM-B), this is considered the best way to go. One cable for each dedicated branch circuit. Dedicated branch circuits only.... No shared neutral multi conductor separate circuit branch circuits!
If the distance from the panel to the outlets is less than 40' to 50' (12-2 with ground) would be ok. Over 50' I would recommend 10-2 W/grd. Many recommend 10 gauge period! One thing about if you install #10 now.... you won't wonder at a later date, what if......
Have the electrician use plastic rough-in boxes for the receptacles if at all possible.
Nylon flexible duplex cover plates.
At the electrical panel make sure the electrician connects the hot conductors of both branch circuits on the same Line, leg, in the panel. If he can on 20 amp breakers directly across from one another.
If you do have to use some type of metallic raceway, conduit, ask him if he can use
MC aluminum armor cable.
Solid core copper only, three insulated conductors in each MC cable. Hot, neutral, and equipment grounding conductor. If he can, stick with the plastic receptacle rough-in boxes.
Your electrician not only has to follow NEC but AHJ (authority having jurisdiction) in your area.