question on Cabling

let's say I have a cable modem and a wired router.

I have my coaxial outlets at point A and my router is at point B, which is quite a bit of distance (across floors and walls).

question is, would it be a better idea to have a long coaxial cable to go from point A to the modem then use a short Network cable to hook up between the modem and router, or use a short coaxial cable and long network cable?
[or does it matter in the first place?]

(I have yet to buy the cables and cable price isn't a concern yet)