If you want to do it right, here is the way it ought to be. First, isolated ground receptacles are a benefit only from reducing EMI and RMI and is well worth the extra copper, IMO. Second, if you are using a subpanel for your two dedicated outlets, it is important that all grounding conductors (the white neutral and the green isolated ground) run all the way back to the main service grounding point (ground rod, utility neutral and/or water pipe). You cannot bond these wires to the subpanel because the electrical load will be split in parallel with the main panel. In plain English, it will energize the subpanel and create a danger of electrical shock to all appliances plugged into circuits between the main panel and the subpanel.
When you install the subpanel, make sure to tell the electrician it is a subpanel. The electrician will then place an isolator (a piece of rubber or plastic) under the subpanel's neutral and ground bar, electrically isolating it from the house grounding system. Then, the electrician must run a separate and dedicated neutral wire from the subpanel's isolated neutral bus to the main panel's neutral bus. Also, a separate ground wire from the subpanel's isolated ground bus to the main panel's neutral bus is required since you are running isolated ground. Most panels do not come with a separate ground bus (grounds and neutrals are one in the same), but you can buy them separately. Now, when you wire your two dedicated receptacles to the subpanel, the neutral and the grounds are uninterrupted to the main service grounding point, even though they terminate at the subpanel. This way, a future electrician need not worry about adding additional circuits to the subpanel.
The point is to have the grounding point be the earth and the receptacles, with no bonds in between.
The subpanel should be rated for at least 60-amps and should be fed from a two-pole 60-amp breaker from the main panel. Use copper wire, never aluminum. I would run the wires from the main panel to the subpanel in EMT and I would twist the wires to cancel common mode noise. The neutral from the subpanel can be run in the same tubing but the ground should be in a separate conduit. If your codes allow, the subpanel should be lugged, instead of having a main circuit breaker. The breaker from the main panel is adequate to protect the feeder.