Linux distribution. Choose your favorite Linux distribution. I personally like Red Hat, but any choice should be fine.
Professional choice. If you’re developing software for a living, it pays to have the best equipment possible. The most valuable asset of professional developers is time, and saving time is usually worth the cost. When analyzing what steps a developer actually goes through during the development process, you’ll usually find that a large block of time is spent in the debugging cycle during active development. (See the next section for more on the debugging cycle.)