Head to Star Tours at Disney's Hollywood Studios - the store at the end of the attraction (which you can enter either through the attraction or by walking on past the line entrance) is packed full with star wars goodies. Best allow some time for him to shop! The lines at the tills can be quite long at times too.
In DTD, there is a store where you can build your own lightsaber. This was a huge highlight of our April '07 trip! I believe the store is "Once Upon a Toy". There was a lot of Star Wars stuff there, also.
Last time we were at the shop at Star Tours they also had the "Build Your Own Lightsaber" setup. But it was a Star Wars Weekend, so not sure it is always there.
Last time we were at the shop at Star Tours they also had the "Build Your Own Lightsaber" setup. But it was a Star Wars Weekend, so not sure it is always there.