so stillen, dc sports, brian crower, ect are "unknown" parts. being in japan will give you different options than living in the states. whats "unknown" there is mainstream market here and vice versa. what popular there may not be popular here. people here in the states will tell you what to do and not to do too that doesn't really make it any more or less right or wrong. when it comes down to it buy the part with the best value, i have only ever had to replace one aftermarket header and it wasn't a quality issue. make sure its a good material with good welds, if two products have the same qualities paying more because a company thinks their name is worth more is a waste of money. hell by buddy wanted an intake for his mazda so i did the research and found that for $60 he could have an exact replica injen intake shipped to his door for $170 less than than the injen. every weld and the fittment was perfect the only thing it didn't have was an injen badge on it and an injen filter, so we ordered a dryflow and threw the cheap one it came with in the trash, total price for intake and filter, about $120 still making ti $110 cheaper than injen and its the exact same thing. research the product not the name.