If you want to do something really badass for your cousin, instead of getting a regular tower, buy some subs and use them as speaker stands for some good stand mount speakers. That basically turns them into really beefy tower speakers. Here is what I would do for around that budget: get two
Hsu VTF-2 mk5s and a pair of
Kali LP-8s. That will come up to about $1600. The cons of a system like that is it would have a bigger footprint than normal tower speakers. It also wouldn't be all that pretty. The pro is that it would have far more dynamic range than any tower that you could buy in that price class, as well as much better bass extension. It would also have a superior on and off-axis response to most tower speakers, so it could be a lot more accurate. Those speakers and subs are self-amplified as well, so you don't need to supply an amplifier. That system would absolutely rock, and no similarly priced tower speaker would be able to touch it.