Don't buy cheap ebay shit.
Oem or better than oem is the only option.
Or just throw your engine in the compactor while your ahead.
There is minimal if any difference, just colors and names.
Those serpentine belts must have a certain tensile strength and elasticity in order to hold it's shape, minimal shrinkage and continue to do so for 60-100k miles.
A lot of race cars like the Indy 500, rebuild their engine every 500-5000 miles. What makes you think they would design a belt to last 100k?