Durrango used to be an SUV that was reasonably reliable but as of today is not so reliable. The Toyota Landcruiser has limited sales so there is no reliablity data available but in general Toyotas are fairly reliable. It is a very good vehicle but finding one in your $8000 price range that is not too old may not be reasonable.
GMC Yukon and Chevy Tahoe (essentially twins) from 2011-2014 are fairly reliable vehicles which usually only have issues around squeaking. Any newer and you have to deal with the redesign which unfortunately have had some issues with Electroinics in addition to the body squeaks. Nothing too major but inconveinent to be sure. The 721 being more of a performance model may have a few more issues as well.
For your price you may find you can get a used GMC/Chevy easier than the Toyota. In my view, all three are reasonable choices although you may find the Toyota slightly more reliable (but in the case of newer cars, definately more reliable).
Toyota 4Runner which is more reliable would also work for you most likely. Best of luck.