Architect and install file server storage system

Architect a secure file server storage system, that includes specific software and hardware along with their associated costs, and cost of installation which would also be done by you. Basically I’m looking for network storage device and architecture that would support a small business network comprised of 3 workstations at the office and 3 laptops that would login remote from other locations. I want them all to be able to access and modify the same files (mostly excel spreadsheets and ms office documents). The system would have to utilize some sort of security like a vpn to ensure the remote logins are actually people that are allowed to access the documents. Please architect something together and include the costs associated with attaining the hardware and software licenses as well as cost of installation. Office is in Irvine, California (Orange County). Must be local to install system. No quotes from out of the area. Local only.