Have a look at the Alpina XB7! Currently, the fastest most powerful X7 available is the X7 M50i with 523 hp / 553 lb-ft, but Alpina is about to best that with its XB7 which could have approximately 600 hp and 590 lb-ft torque from its tuned twin-turbo V8, possibly matching the power output of the 2020 Alpina B7.
Per usual with Alpina models, besides a tuned engine and upgraded transmission, the XB7 will feature custom Alpina paint, bumpers, wheels, brakes, exhaust, suspension and interior.
Whether the XB7 comes stateside has not yet been announced, but let's hope that it becomes the first Alpina SUV to be available in North America.
Updated October 25, 2019 with Nurburgring testing video.