If your walls are ripped open, then sure run some OS2 everywhere, but Cat 6A gets you 10GbE at 100m, but even 'only' Cat 5e or (plain) 6 gets you that speed up to 55m (per 802.3an):

* https://en.wikipedia.org/wiki/10_Gigabit_Ethernet#10GBASE-T

* https://en.wikipedia.org/wiki/Ethernet_over_twisted_pair#Var...

Why the need for faffing about with media convertors, at least with-in your domicile? (Fibre outside / to the garage certainly makes sense.)