Get 200+ Gigabit Ethernet through router/switch

If I have 200+ Mbps wired ethernet Spectrum Arris modem, should I install a wired switch or hub which will split the connection between hardwired PC's and a wireless router or a newer fancy gigabit wireless router? Will the new switch or router reduce the speed very much? I ask because I have very little use for wireless connections but would like to keep them available and still get close to the speeds I get when connected directly to the modem. I could by a wireless modem but I was looking into something more economical since the modem is free.

I've been using the Arris device + local switches + local wireless access points (which is a router that's used for wireless connectivity to a single wired connection) for two years and a bit longer. Works like a charm here at my house. My wired PCs get between 40 and 60% of my rated Internet speed of 940 Mbps, and my wireless PCs get up to 80% of their rated connection speeds (which varies by device: I've got some 802.11ac devices that get up to 400-450 Mbps, with older, slower devices usually getting between 110 - 290 Mbps depending on specifics). If it works like that for me, it should work like that for you, as determined by the actual maximum download/upload speeds for your particular Spectrum Internet connection.
HTH,
--Ed--

Thank you Ed,
I should have asked if I hook a switch to the single port on the modem then there will only be one IP address for the switch to split. If I want multiple devices online at the same time then they need a router to assign IPs.

Thanks guys, I was afraid of that, I doubt if it does DHCP, it is an Arris TM1602AP2 and I do not have the password for the advanced settings. Getting a gigabit router sounds like the best option.

I guess it depends on the Arris device one has. I just checked, and I've actually got a Technicolor modem, which hooks into an Arris device that offers 4-ports of GbE switching, 802.11ac wireless, and router capability. I also have two subsidiary switches, one downstairs in my office, the other upstairs at my wife's desk to provide wired Ethernet ports for a network printer, her PC, and additional guest wired hookups should they be needed.
Thanks for looking up the specific item, @NavyLCDR.
--Ed--

Thanks Ed, you got a better modem.

Thank you NavyLCDR & Samuria for your excellent advice.

Update: Upgraded to Linksys WRT1900ACS and it works great!