Contreras as baseball's best in '05-'06 is a stretch. Very good-occasional excellent in '05 and good-very good in '06 seem better descriptors. In 2005 both Buehrle and Garland put up better metrics among several others across both leagues.
Contreras was a pretty smart pitcher and I'd say had a leg up on Kopech WRT 2-pitch style, at least in varying speeds/location and even delivery. i.e. He had a savvy that experience might bring to Kopech, but it's pretty early in K's career to expect him to be a grizzled vet. In any case, to last in modern baseball, K needs to get a third pitch going. But right now, his slider isn't exactly reminding anyone of Steve Carlton.
Right now, I'd say the Jays, Yankees and Stro's have a good chance of lighting him up.