For a roof rack, the short OEM rails open up a world of aftermarket options.
Prospeed seems to be a big favorite.
There is also Voyager, FrontRunner, Baja, Rhino, and Safety Devices, amongst others I am probably forgetting.
Keep in mind that the LR4 is already a tall vehicle. My LR4 on 265/65/18 tires barely fits into my 6'5" work garage at stock suspension height. The Prospeed is the slimmest of the options, but it still adds a little height to the LR4. If you have to enter parking garages a lot, it's something to think about.