There are a gazillion two button mice, many of which are very good (Logitech is my favorite). Buy one of those, and be thankful that you're not spending the $50-$80 Apple would charge for their take on a two button mouse.
And Apple's not choosing not to make one because they "don't want to copy the PC world," it's because there's no reason for them to not keep making and including a one button mouse. They are the only company that still makes one button mice. If you want one, buy it. If you got one with your computer and you don't like it, sell it. A new one is very cheap.