Get your own Arris Surfboard without the Router elements, make sure it is DOCSIS 3.1 and the maximum bandwidth exceeds your current speed provided by the ISP. I would recommend the SB8200 but check with your ISP to guarantee that they will accept a connection with that model.

Purchase any router you like. I’m sure you can find plenty of router recommendations online. If you wanted a rack router you could even get one of those, but it sounds like you just need a solid wireless router that has good coverage and a few ports on the back, which is pretty standard.