To connect the NAC42, SNAPS and NAP110 together you will need a pair of SNAIC4 cables. Be sure to only use genuine SNAICs here. One SNAIC connects between the NAC42 and the SNAPS, and the other from the SNAPS to the NAP110. The SNAPS provides power to the NAC42 and also takes signal from the NAC42 through two the NAP110.
To connect to the speakers you’ll need suitable speaker cable (NACA4/NACA5 recommended) fitted with 4mm banana plugs. I would recommend Naim’s SA8 plugs which can be fitted by a Naim dealer. You’ll need at least 3.5m per channel of the speaker cable.
Take a look at the FAQ section here which tells you a lot more about speaker cable recommendations, identifying SNAICs etc…
Do note that the capacitors may be past their best and may be in need of servicing. If you’re in the UK then you have the choice of the factory or the factory approved services of Class A, which can work out to be more affordable.