If his budget is fixed at $599, I would start with two good bookshelf speakers (Klipsch, HSU, Arx, Cambridge, KEF all have bookshelf speakers in this price range) and an inexpensive receiver. This alone will likely exceed the sound quality of the Bose system, and he can always add a sub later.
Aside from a poor value proposition, my main issue with a Bose system like this is that you can never upgrade it. The frequency response of the satellites is so poor that the "bass module" crossover is something absurd like 250 Hz. Therefore, you could never upgrade your sub at a later point because no traditional sub plays up to 250 Hz.