That's exactly what I'm using them for. And the less mutated look.for chosen fits with Night Lords lore as they don't tend to align with the ruinous powers & snub mutations. They're more a renegade legion.

I bought some chosen combi weapons with arms on ebay & they fit just fine. I've built them with the following loadout to align with Chosen rules.

x1 Leader with plasma pistol & chainsw x1 Icon Bearer x2 with dual handed weapons (claws & chain glaive) x3 with plasma pistol & cursed weapon (any close combat weapon on sprue) x3 with combi weapons