Sorry for late response. As I said to the others the whole internet of my country was down. I had no access to internet.
I was told that the wine which is made by concentrate would be thin. I thought that if I handle the acidity level of my wine then it wouldn't be thin anymore. (Although I needed acid blends for some recipes which I found on Jack Keller's site)
Wine from concentrate will be "thinner" than wine made from grapes. I think the "thickness" comes from the grape skins. But, for your first batch, you should just try it without adding too much extra stuff. I don't think more acid will help you. Can you obtain real grapes? You would be better off making a fruit pack out of 1 or 2 kg of crushed grapes.