As title says, I'm cutting cable and looking to purchase a router modem instead of renting it from Comcast.
Router is located mid level, the router they provided was providing adequate signal. Not sure if I should go with a all in one unit or purchase them separately.

Separately, budget and rest of devices will dictate what you wanna get.
As for modem your limited to what works with your ISP.

Total budget- $300 can probably push it a little more if needed, modem I would need for xfinity, 250mbps plan

literally any modem then
might as well get a docsis 3.1 to be
future proof
rest of budget can get a mesh of routers

I’m running the Arris Surfboard docsis 3.1 router modem combo and it’s more reliable than the one provided by my cable company. And most any modem should work. This has WiFi and 2x 1gb Ethernet ports and it runs my 500mb connection no problem

ITs a 600 mbps plan, any other recommendations?

If you're paying for 600
And comcast equipment isn't
Getting 600
You call them and they owe you money

i just dont want to rent from them anymore and am clueless about modems routers lol

Docsis 3.1 modem that can do 600+
And a router that can do the same.

Amazon is your friend here

https://www.tomsguide.com/us/how-to-buy-cable-modem,review-5607.html
https://www.windowscentral.com/how-to-choose-best-router
Literally just google
Got my modem from Costco
Got my router for rgb big dick status