What vanilla armour should my Redguard warrior wear? He uses one handed and block while using a scimitar, but nothing seems to fit exempt from the Hammerfell outfit. Help?

Well, I am quite positive on the fact that, if this alleged downloadable content known as 'Redguard' will turn out to be actual, and it will indeed bring Redguard-related goods, then you will have quite many interesting things to wear. In the vanilla game, not so much, a part from those exotic cloths those henchmen from Hammerfell wear in a certain side-quest.

You can use ebony armor (or parts of it) . Most mosques in the Alik'r desert are dedicated to Ebonarm the God of War.

Hmmm I guess.

Coming from Cornelious the pirate, Ragged trousers, or actual redguard clothes

Are you on PC? If yes, see http://skyrim.nexusmods.com/mods/13500.

Yeah, but the OP might as well get the entire immersive armors pack also.

OP:

My Redguard was traumatized with being captured, accused, convicted without trial and nearly beheaded. As a result, she swore to never be defenseless again, and doesn't rely on armor. Try the Hammerfell garb with the 'flesh' spells to protect yourself. If Redguard dlc ever comes out, pick an armor then.

Sidenote: It's stupid that male Redguards get ethnic hair choices, but female Redguards don't.