Alright, so I've been revisiting Oblivion for the first time since Skyrim happened and had forgotten how great it was. Anyhow, I'm lv 12 now and scouring Cyrodiil for gauntlets and a helmet to complete my orcish set and can't find anything. I have found 3 cuirasses and several breeches and boots, just can't find those last two pieces. Don't need the shield as I am using Spell Breaker, and I haven't found a single orcish weapon yet, but I'm using Volendrung so I'm not tripping. Any suggestions on how I can find those last two pieces of armor? I've just been bouncing from dungeon to dungeon, already completed main quest and fighter's guild.

I'd say marauders are your best bet to find concentrations of heavy armor in general. Helmets are a little harder to find and I think the best place to find an orcish one is on the head of a marauder warlord. :Your best bet is to try and find one before level 15 when they will be joined by ebony helmets.

Here's a link to marauder dungeons: http://www.uesp.net/wiki/Oblivion:Marauder_Dungeons

Well, worst case, when you hit level 15, the vendors will start selling orcish.

In the meantime, I'd suggest frequenting Marauder dungeons, like Fort Alessia, Nornal, Fort Blueblood, Rockmilk Cave, etc. You're likely to find somebody wearing what you're looking for.

Thanks for the responses and the link is nice! I've been tearing through the places listed and the new problem I'm encountering is that almost no marauders wear gauntlets or helmets! Shame because I found a nice enchanted orcish chest piece...