My friend wants that as a gift and I wasn't sure which would be best. Any ideas or suggestions?
For the Ottoman Military i recommend "A Military History of the Ottomans: From Osman to Atatürk" and "Ottoman Wars, 1700-1870: An Empire Besieged"
Did you take a look on our Books & Resources List? Granted, sometime it's hard to find exactly what you are looking for.
Ottoman history is tricky because it covers so much time. Anatolia during the early conquests of Osman is so very different than the 19th century Empire during, say, the Tanzimât reforms. The Empire had such a long history and (like any long-surviving polity) re-invented itself at times. (Although the contemporaries would rarely explicitly see it that way.) What I'm getting at is that there's hardly any commendable single volume history book on the entirety of the Ottoman Empire that is not already enormous.
Well, there's one I know of: Finkel, Caroline: Osman's Dream: The Story of the Ottoman Empire, 1300-1923. New York: Basic Books, 2006. -- But this one is also over 700 pages if I remember correctly.
Other things that you might be interested in, although they are not single volume history books of everything Ottoman: