Cold dilled matzo balls in a salad sounds interesting!
With all due respect to GB, I do not recommend using a mix. None of the mixes produces a result as good as the real thing and you save very little time using a mix over making them from scratch because the prep and cooking involved are what takes the most time.
If you have a Jewish foods section in your supermarket, you should be able to find matzo meal there all year 'round, and just about every company that makes it has a recipe printed on the box. Make sure you use very cold water (some cooks swear by very cold seltzer in place of the water) when you are preparing your mixture and don't forget to cool/moisten your hands with cold water before shaping the balls.
You might want to try Chefellas' suggestion of quartering them for a salad, because even when they start out very small they do tend to expand, especially if you prefer the light and fluffy variant. And if you do prefer the light and fluffy variant, be sure you add all the formed balls to the cooking water at pretty much the same time, cover the pot, and do not uncover even for a second during the cooking.
(If you uncover them during the cooking, you will get the cannonball variant.)
Here's a recipe to try:
4 eggs, slightly beaten*
4 tablespoons of oil
4 tablespoons of ice cold water
1 cup matzo meal
1 teaspoon of salt
1/2 teaspoon of pepper**
*I like to separate the eggs and beat the whites almost to a meringue, mix up everything else, and then carefully fold in the beaten whites -- this produces maximum fluff.
**I omit pepper and instead use garlic and dill to taste.
Place all the ingredients in a large mixing bowl and mix well. After mixing refrigerate for one hour covered in the refrigerator.
Fill a large pot with 8 cups of water and one teaspoon of salt and bring to a boil. The matzo balls will expand in the pot as they cook, so choose a large pot to allow for expansion. After the water comes to a boil, reduce the flame to low. Take the mixture out from the refrigerator and in your hand gently make the balls. Make sure that your hands are wet before proceeding to make the balls. Slowly add the newly formed balls to the hot water.
Cook for thirty minutes, then turn off fire, but keep the pot covered and let it cool for another ten minutes.
Store in refrigerator until ready to serve.
If serving in chicken soup, do not add the matzo balls to the soup until a half hour before serving. Leftover matzo balls are good reheated in soup, and some people enjoy them sliced and fried in oil.