Janan
Creating a new track with SCs matching your portal would be a good idea.
Is your ESS in the old track already customized? If so, you can forward your existing ESS SC from the Assembled tab to the new track.
Just enure that you have enough disk space as ESS is ~500 megs.
Are you going to be updating an existing ESS DC or creating a new one? If you will be creating a new DC, you should consider adding it to a custom SC. Deploying the custom SC will be a lot quicker than deploying ESS.
Stefan