My vote would be Orc armor. Check it http://wolflore.net/download/file.php?id=7007&sid=244298aa1eff870c42bc190d2fd79e64&mode=view!
I you make its fur black, leather armor looks really good on khajiit.
I agree but don't use vanilla leather armor, because it looks terrible in-game. Fortunately, there is SpritedTreasure's http://www.fliggerty.com/phpBB3/viewtopic.php?f=102&t=4954 mod to correct that and I've using her mod since the day she release it, in fact I cannot play Skyrim without it.
I'm in love with glass armour at the moment, that glass helm has to be the sixiest thing ever invented . No idea how it looks on a cat though...
I can't do it but http://i.imgur.com/WeupH.jpg looks good in Tsuns Armor (with arm bandages) and an Alik'r Hood.
Uh...that pretty much looks like Thieves Guild Armor.
No, it's not, but the OP didn't say anything in the original post about keeping it light. It's funny, but somehow when i see a khajiit with a battle axe, I think of that Khajiit wearing heavy armor in the Arena in Oblivion... I've played Khajiits as straightup thieves, and as warriors in heavy armor, and they do quite well in either case.
EDIT: My mistake, I guess I should have read the title a little more carefully.
Hold guard armor; a Khajiit with white or black fur in Solitude guard's armor would look great, I'd think. For boots, I'd go for leather, hide, light or heavy Imperial boots (maybe scaled, also), and hide or scaled bracers (or nothing on the arms).
If I were more of a cat freak, that would totally get me into playing a Khajiit.
yeah, hold Guard armor looks good on Khajiit.. Solitude and Whiterun especially