I am not throwing mud at you and am not saying that you are bad at what you do, I just mentioned the way that you said it doesn't seem like you cared about your clientele, I understand that there are diffirent parts and different brand names and that a lot of them will do the same job as the name brand one, there are also some that will not.
So Once again It was your attitude toward your customers that I commented about and I still think that if a customer wants a certain part then you should install it for them, even if they have to get it themselves ( Of course only if it is the right part ).