I run rhino rack. The quick detach bars have been super easy over the years. Looking back I’m glad I did this because the platform racks cover all the glass and make the truck very dark inside. These attach to the factory rails.
Unless you absolutely have to I would dissuade anyone from putting heavy loads on their roof. It only increases the CG and has a negative effect on all driving dynamics. It doesn't help your woeful fuel economy either..
Like most SUVs and light trucks the payload of the LR4 is not great and every do-dad added takes away from the number.
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.
I have the Rhino Rack Pioneer platform on their backbone mounts. It works pretty well, doesn't stick up a lot, and is very flexible. The downside is that I think the channels are really wider than they need to be, and it's pretty heavy, and I had to make an air deflector for it.
After nearly a year of considering which rack to go with, I narrowed it between a Gobi rack and ProSpeed. Pulled the trigger on the ProSpeed rack due to it's ultra low profile (which I need to sneak into my garage). My complaint about the ProSpeed rack: The tubing isn't rigid enough. Secondly, the plastic sheet plates aren't as rigid and ofcoarse block out the light through the moon roof. I'll be modifying mine to have all metal mesh that is strong and will allow light to come in.