5000mbps home router

Hi,

I live in a condo that my ISP provides 50/500/5000 Mbps Internet connection.

Currently I am using 500mbps but I am wondering what kind of router/switch is suitable if I upgrade to 5000Mbps internet.

On their website, they mention that a "Multi-gigabit Ethernet (5GBASE-T)" is required.

Can I simply connect a CAT6 wire to the WAN port of a RAX120? Or can I use the multigig port as a WAN port?

I see that RAX120 provides 4 1Gbps LAN ports, are there any switches that I can add to my router to get 5Gbps LAN outputs?

RAX120 has a 5G multigig port but the RAX500 has 2.5multigig port. So I think the higher model would not be suitable, am I right?

Thanks