Have you considered trying the oem crossbars? They’re 20% off right now direct from Lexus.
I’m not sure how oem compares to aftermarket like Thule etc. but I’d rather go oem than a random crossbar from eBay etc. my 2c
Lexus GX 550 Gx crbr resin rail - PT97060246 - Genuine Lexus Part
Gx crbr resin rail. Lexus GX 550. Genuine Lexus Part - PT97060246 (PT970-60246, PT97060242)
parts.lexus.com
I’m not sure how oem compares to aftermarket like Thule etc. but I’d rather go oem than a random crossbar from eBay etc. my 2c