Coaxial cable confusion (help)?

Alright, i am switchin rooms. We have Charter, hwich run the internet and cable through one coaxial cable. My new room doesnt have a coax cable place in it. We can run new cable in there but since our wireless router will be in there we think we should buy the best coax cable. Which is? What we r gonna do is put the coax cable in their and split it sending one part to the router and one to the tv. Wont the spliter reduce quality too? So what should we do, buy a HQ 50' coax cable for 100$ and a HQ spliter for 30$? Just so the internet will be good< cuz we do got to run it a good ways. HELP I am scared when we run it that far it will have bad quality.