You should have no problems with your 4 x 8 layout by putting the command station & booster at one end. For a 5 amp system you could wire up the DCC busses using
18 ga zip cord or 16 ga speaker wire. You can still find 18 ga red & white twisted “bell’ wire in some stores. Splitting up the layout into 4 power district blocks with disconnect switches is a noble idea, but somewhat overkill. However, at a later time you
may want to replace or supplement the disconnect switches with electronic circuit breakers to help protect your fragile N scale equipment.
I am in the planning stages of a N Scale layout. I am using a 4'x8' layout.... According to my layout program I have a total of a bit over 90' of track... I have it broken into 4 different blocks. My question is since I really want to locate my complete controls
at one end of the layout and not the center.... can I just use a lager size bus wire to address any issues with length? I plan on using a Digitrax SEBX Super Empire Builder Xtra with 5 Amps..... I would be running all of my Bus wires to a switch box that has
DPST Switches that will allow me to isolate each Block. I plan on installing either Circuit Breakers or use the 1156 bulb option for each block. I have rambled enough and for this I apologize... Any and all help or pointers will be greatly appreciated.