For a "Fighting Knife", if you have some training, I would go with the smaller 5 -7" blade like the BK7, a Ka-Bar, Air Force survival knife (though I personally would not get anything with saw teeth) or the Cold Steel knives you have been looking at. Personally I like the UWK's design. I would definately opt for the superior strength of Carbon steel over any stainless knives though...
Assuming you have the leatherman or multi-tool thing covered, people far more knowledgable than I have already commented that you will probably never have a 'knife fight' over there & thus it is likely that your 'fighter' will pull more duty opening MRE's than it will with "wet work"

Also, from what I hear, your unit CO may not allow you to wear a fixed blade much of the time (this seems utterly foolish to me but hey, what do I know...).
However, I would suggest that the Middle East in general is definately a 'knife culture'. Thus, a large blade may be something of a badge of honor - at least to some of the locals. If it were me, I would take as large a blade as I was willing to hump around with me - a big, bad ass Bowie, like Ontario's Marine Raider, or Cold Steel's Trailmaster would be kinda cool - but probably alot of weight to carry all the time, especially when compared to some of the smaller knives referenced above.
Here's an idea; why not carry a big carbon steel knife of middle eastern style such as one of these Jambiyas from Windlass Steelcrafts or even a HI Kukri? (perhaps a little more than the $80 you mentioned but not too much more):
http://www.atlantacutlery.com/webstore/showproduct.asp?hidProductId=400726&hidSearchPosition=5
http://store.yahoo.com/yhst-7333098713883/12inchak.html
Good luck over there my friend, whatever knife you choose
