You need a 22mm spade bit to cut the holes for the shanks. Then shanks and either hosetail and nuts or the qd shank connectors sold by CB.
Then, gas manifold/t-pieces to split up the gas out and beer/gas line to get gas from cylinder/reg to nrv, then more line to pass into keezer, use 8/10mm hole to pass line into keezer through collar, seal with silicone. Put manifold/t-pieces inside keezer of make multiple holes in collar if you want to be able to turn individual kegs off from outside.
Inside, kegs, gas disconnects, line. Beer out disconnects and line. Shanks, taps, handles.
For temp control, stc or other temp controller setup. Set keezer to coldest setting and set temp on controller.