I need advise on setting up a home network. I have a main house on the upper two floors and a basement suite. I want to run two separate networks on the same internet account. I plan on going from the line in to the gateway bridged out port 1 wan to a 2 port network switch to two separate routers. One router has wifi and 2 wired ports in the suite and the other router has an 8 port switch running to the various rooms in the main house with the wifi turned off and a mesh network attached to two of the lines on the main and upper floor. Will this work? Will the suite and main networks be isolated? Do you foresee any issues with this?
Whether this will work depends mainly on whether the ISP provides two separate network addresses to the two routers. It may be necessary to use IPv6 or to purchase a separate IPv4 address. Another option may be to create two separate virtual NAT address spaces. How isolated that will be depends on the equipment and how it is set up. It would help if we knew the ISP.
What is it you're trying to accomplish? You seem to be going through a lot of trouble. Is one network supposed to be for guests? Many routers can provide a guest network via Wifi, in addition to the main network.
It's better to describe the target, than how you think it should be accomplished, when we don't know what the plan is.
It sounds like the OP wants to provide internet to a separate "suite" in the basement but keep it on a different IP address. Not sure how legal that is or if it would provide any legal protection in the event of illegal activities on the other address. Some ISPs will provide two IPs with that kind of setup. The obvious advantage would be to completely isolate the two LANs and provide protection against snooping or hacking on the local network. That could be done in other ways by setting up two separate subnets.