You DO NOT need to use another router.  One is sufficient and 200 feet of wire would not be a problem.   For stronger wireless, you COULD add another WIRED access point to your network.  In fact (I) do exactly that.  I have a AP near the front of the house, and another near the back. I have about 30 "devices" on the network.... but ONE router / DHCP box is quite sufficient for it all.   Your issue is more than likely multiple DHCP servers.  For YOUR network, that is probably not needed.

 If you like, I will help you further via phone (MUCH MORE EFFICIENT THAN TYPING)  Private message me with your number.