Your Van Damme cable will be fine. If you want a perfect match for your amplifier, I would use Naim’s NACA5 cable with the Naim banana plugs that are supplied with the amp, but the cables you already have will work well.
Naim amps are, by design, sensitive to the type and length of speaker cable used. The safest bet is to use Naim cable and plugs, as they are designed to be a good match, so you could try them if you like. Still, the Van Damme cables you mentioned will be fine. If they sound good to you, there’s no need to change.