Fiber management question

Hi!

For some context, I work as a network technician and it manager in a business where we provide IT services and PBX installation and service. Another division of the business resell ISP services.

We share a building with 3 other businesses and have a dedicated Fiber connection with a single IP address and decided to upgrade our service and get more IP addresses and my boss would like to provide internet to the other renters with their own IP address, router and equipment behind.

I would like to have some insight to how I should proceed with that request as we want to limit the connection of the other renters to a specific speed. As we have 2.5gbps, we would like to give 250 to 1gbps. What I thought of was to have a wan facing switch and provide an IP address in our range to the renter and to some ACL rules (as an exemple with a microtik switch).

We usually use Fortinet, Ubiquiti and Microtik networking equipment, but, I could buy other gear if needed.

Thanks for the help!