The 4Runner is actually our most popular customer vehicle- so we are well-versed in what works best.
First things first, your stock crossbars will not work. They are too close to the roof of the vehicle to allow you to tighten the hardware underneath. You will need an aftermarket set of crossbars or a platform rack in order to mount up a tent. We always suggest crossbars as they are plenty strong for installation and much easier and cheaper to deal with than a platform rack.
The Malone bars we sell on our accessory store page are a great option. They simply clamp onto the side rails that run down the 4Runner and replace the stock crossbars. They are stronger and of course allow your hands to fit under to tighten up that hardware. The size 50" bars work great.
As for tent choice, the most popular is the Falcon tent. It is super low-profile and looks sharp. Check out our Instagram @roofnest for more pictures of that combo than you can shake a stick at.
While the Falcon XL will work, almost everyone finds the extra width and subsequent overhang too much for the 4Runner. 95% of our customers go with the normal size Falcon. The regular size Condor and Sparrow, as well as both Sparrow Adventures also work great!