I was also going to suggest Hummus, but I think you should make it yourself. If you have a blender or food processor, it is basically just garbanzo beans (canned chickpeas) and olive oil. You can add things like bell peppers or lemon or jalepenos and make a whole variety of Hummus's.
1 can chickpeas, rinsed and drained
1/2 cup non-fat plain yogurt (sour cream can be substituted if you need to)
2 tablespoons lemon juice (recipe says fresh...but yeah, right)
3 garlic cloves (or from a jar)
2 teaspoons olive oil
1/2 teaspoon salt
1/2 teaspoon ground cumin
Stick it all in a blender and puree until smooth. Add more olive oil if necessary, a little a time.
I am sure there are other good recipes out there, I haven't tried this one but a friend passed it on to me recently. allrecipes.com is a great website for recipes (check there for a good bruschetta recipe too). Packaged hummus is pricey and seems fancy, but chickpeas in a can are cheap! Then you could add a few types of cheese or cheese dips and it will seem a lot fancier. You could also make your own cream cheese dips with plain cream cheese, add in veggies that have been very slightly steamed or blanched for a second in boiling water, then dipped back into cold water, and re-refrigerate it.
For your crackers I would do some basic ritz or wheat thin type crackers if you must bring crackers, and then you can make baguette crisps also- they are great for the bruschetta. Buy some day-old baguettes (probably 2 long ones for that size group) from your grocery store, they are usually pretty cheap. Slice them very thin, lay them out on a cookie sheet, drizzle olive oil all over them, and toast them in the oven. I tend to over-buy bread and it is always turning stale. I had to bring a dish to bunco a few months ago and completely forgot to shop, so I pulled out the stale-ish bread (it was quite hard actually) and did this, and made a packaged spinach dip and added frozen shrimp to it and everyone raved. The baguette crisps you buy in the store cost a fortune. Now I just buy the old bread and stick it in my deep freezer. And then pita breads cut into triangles are good for the hummus.
Good luck!