orks in inquisitor

Well, the entire point of the game is to deal with the subtle workings and in-fights of the Inquisitions. Orks aren't known for their subtlety nor for their, uh, relationship with the Inquisition

That aside, there aren't any Ork models for =][=, but you could probably convert one from one of the bulkier =][= models. An all-Ork band is basically a no-no (same with all Eldar, all Tau, etc). But there is one clan of Orks (can't remember their names) who does mercenary work. A single Ork in a radical Inquisitor's band might be ok.

Well it's been one before. Heres a link to an example I found on the net, bottom pic to the left.
http://www.the-waaagh.com/gfgallery.htm

I believe the clan's name is the Bloodaxes. They're clever for Orks, and they'll do anything for money.

It is feasible to work pretty much any thing into =][=, mini wise, some of the mutants would be a godo start for a conversion, stat wise the alien generator plus comparison to other archetypes would help

I was thinking of a similar thing for my games, as they'd make a good opposition. I'm guessing the stats would be like in 40k - High strength and toughness, low speed, almost nil willpower...
From a modelling point of biew, a warboss or even Thraka himself might just be big enough to make a decent =][= size model. Don't see what's wronmg with all orc warbands, either - the rules are there to be versatile, and Ordo Xenos foesn't exactly ignore them.