The horizontal run can be 90M, from here you can then have patch leads at either end. All 8 wires are only required if running Gigabit speeds, if only running 10/100 then only 4 cores(2 pairs) are used. Looking at the original diagram all you need is a CAT5e cable from the router to the PC-no need for a switch that end unless you want multiple Ethernet devices at that end.