Hi,
I would suggest running FS and FSHost on the same machine. Although it sounds like a good idea to separate them, it actually causes lots of networking problems when you're using a router, because you can only forward the FS ports to one machine at a time, and you need them to go to both machines.
FSHost uses very little of your CPU, so most people are able to run both on the same machine with no problems.
Be sure to forward all the FS ports in your router to the one machine and then it should be fine.
Thanks,
Russell