The amount of muscle you gain or the amount of fat you lose will be mostly DIET dependent, not drug dependent.
If you are looking to add like 50 lbs, Winny and Var are not the top choices. Winny and Var are mostly to add strength, but they ARE ANABOLIC SUBSTANCES. This means that they HELP build muscle. The additional muscle has to weigh SOMETHING.
Drugs cannot ONLY increase strength. Increasing strength can be done through explosive moves, heavy weight work, and progressively lifting heavier and heavier. But this will also build some muscle.....
You can keep weight down through a calorie-reduced state. This will help keep muscle (and fat) gain to a minimum....BUT....it is hard to REALLY train for strength in a calorie deprived state. Calories=energy. No energy means that you will have a hard time liftin/working hard enough to really maximize your strength.
Not sure what you are look for, or what your goals are. It is hard to have everything with NO drawbacks. If you are trainging for something SPECIFIC, you'll get better answers if you CLEARLY state what you are looking for.