New
#21
From your pictures posted, you seem to think that your WiFi router should be up on that empty ledge sticking out like a sore thumb.
Also from these same pictures I see lots of places to conceal your devices Simply mount them on the dark paneled walls or behind your monitor anywhere on the wall vertically or upside down horizontally on the underside of that ledge, they can be easily camouflaged by existing or added decorations including LAN wires.
Antenna length is determined by frequency and wave length. Higher the frequency, shorter the antenna has to be. Classical, half wave whip antenna for CB radio was 102".