Gigabit internet service

That is a cable modem, Gigablast would only require you to have a powerful router, they install a new fiber modem in your home.

With Gigablast, they install fiber from the pole to side of house or into house, to a fiber modem or ONT (Optical Network Terminal). That turns the fiber into ethernet and a Netgear router is included, but you can use anything with WAN DHCP. 

Whole point of getting fiber is you don't use coaxial anymore. So no coaxial cable modems. Though it is still used for cable and can be used to network via MoCA under the right conditions. Fiber changes everything.