Security infrastructure design document

I’m studying and need help with a Computer Science question to help me learn.

Overview: Now that you’re super knowledgeable about security, let's put your newfound know-how to the test. You may find yourself in a tech role someday, where you need to design and influence a culture of security within an organization. This project is your opportunity to practice these important skillsets.

Assignment: In this project, you’ll create a security infrastructure design document for a fictional organization. The security services and tools you describe in the document must be able to meet the needs of the organization. Your work will be evaluated according to how well you met the organization’s requirements.

About the organization: This fictional organization has a small, but growing, employee base, with 50 employees in one small office. The company is an online retailer of the world's finest artisanal, hand-crafted widgets. They've hired you on as a security consultant to help bring their operations into better shape.

Organization requirements: As the security consultant, the company needs you to add security measures to the following systems:

An external website permitting users to browse and purchase widgets
An internal intranet website for employees to use
Secure remote access for engineering employees
Reasonable, basic firewall rules
Wireless coverage in the office
Reasonably secure configurations for laptops
Since this is a retail company that will be handling customer payment data, the organization would like to be extra cautious about privacy. They don't want customer information falling into the hands of an attacker due to malware infections or lost devices.

Engineers will require access to internal websites, along with remote, command line access to their workstations.