Suggestion on buying a single speed 29er mountain bike I'm interested in buying a single speed mountain bike for about $400-600. Can anyone recommend me one? 

I tried buying this http://www.redlinebicycles.com/bikes/mtb/2012-monocog-29er but it is all sold out. I'm 5'6" so I need a small frame for a 29er. I would like the bike to be in a darker color like in the link if possible. Nothing like white or bright colors on the bike as it's main color.
SE Stout is a single speed mountain bike that runs relatively cheap.  

If you're confident in your ability to put it together properly, you can find them at bikesdirect for around 350. 
http://www.bikesdirect.com/products/se/stout.htm

It's got tabs for disc brakes so you could upgrade in the future, but comes with V-Brakes stock.  I have a few friends who have these bikes and really like them.