EDSITEment has several lessons on colonial American which contain material and student activties you could adapt for your purposes.
This is a great project!! I have done brochures in the past but for only one colony. I like the idea of all three on one. I had created a Tic-Tac-Toe choice board to cover all three regions but I just may save a choice board for later and steal this idea. I am attaching the Tic-Tac-Toe file.
I have kids research one of the three regions- This is a good GSPRITE activity (geography, social, political, religion, technology and economics). Each student get to choose which region they want to research, then make a colorful poster. Then, each student makes a list of 10 questions that can be answered by looking at their poster. I have around 130 students, by the time I go over the questions I can come up with 35 to 40 good questions- I try to make sure everyone sees a question that is very similar to something they wrote. I give the students 3 walls to hang the posters- one wall is NE, one is Middle and the other is Southern (obviously!). When the posters are up and the questions are printed, they walk around the room answering the questions. It works like an art gallery- they learn a lot and really seem to enjoy it.
Here is a free lesson that does the trick! I put everything you need handouts, chapter, and interactive student notebook pages all in one doc. Here's an overview:
In this lesson, students learn about the similarities and differences among the New England, Middle, and Southern Colonies. In a Problem Solving Groupwork activity, students work in groups of four to create a Colonial Fair booth that promotes one of eight colonies. Students then visit the booths and evaluate the pros and cons of living in each colony. Afterward, students read about the colonies and reconsider their initial evaluation. Finally, students apply their learning in a Processing assignment.TCI Lesson_Comparing the Colonies
For honors sophomores, I did a project called "Character of the colony." They had to imagine one colony as a person--how would this person act, based on the character, how would the person look? I'd imagine you could do the same thing by grouping the regions to come up with what's common to the colonies in that region.
Let me know if you're interested and I'll send you the assignment I used!