I would probably do something like the chrome armor, a dark grey helm, and the rest of the soldier's garb black(possibly even a black cloak). This would give them a somber feel, as well as a glimpse of the height from which they have fallen. But, as you said, it's a matter of opinion.Matter of opinion, I guess... I COULD see the chrome armour used for PJ Gondorians, but I (as just about everyone here ought to be able to predict) don't really care for the movies as my source of inspiration. I see the Gondorians in light of how the book describes them: as a sober, noble race (hence, I would use black or dark grey helms/armour over chrome for most), and somewhat "fallen" from the great days of old (hence the chrome of Ar-Pharazon becomes the dark grey of Denethor).
I do think that Vladek(KK2:1 version) has great armor for minions of Sauron. Black, with what could be a red eye on it. I put it on my orc-chieftan.