gizmo, I am not familiar with any of those kits but I did look them up on Amazon. They appear to be 5.1 liters juice kits, which means they are highly concentrated and will require about 18 liters of water to be added. My experience is that the greater the amount of juice provided in a kit, the better the kit and thus the better the wine. I use a minimum of 15 liter kts. This is not a hard and fast rule and there are exceptions, particularly in white wines.
I would expect that the wine produced by your kits will be very "thin" and the benefit you will gain from making these four wines is the experience you will acquire. I would not begin experimenting with additives on the first try but I suggest that, instead of making all four wines, you start by making only two, a red and a white. See how that turns out and talk to people on this forum about what can be done to improve the next two wines, e.g. adding raisins, bananas, other fruits, etc.
Good luck with your project and keep us up to date on your progress.