One thing that I have found both from my own experience as well as friends’ is that often people say they want someone extroverted or introverted and that is not really what they mean. Really they may be referring to a certain quality that is important to them that they associate with extroversion or introversion. For example, I always said that I wanted someone extroverted and then I realized that I meant someone with good social skills and self-confidence. I have a friend who wants someone introverted because she associates introversion with social skills and self-confidence.
It may be kidai for you to think about whether or not it’s the extroversion/introversion factor that’s important to you or something else. For example, maybe what you really mean is that you want someone who is a good listener.
It is also important to remember that people often end up with someone different than what they thought, so on the one hand, you should pay attention to your instincts and feelings, but at the same time, try not to be too rigid. Try to hear what the specific girl is about and don’t just label her as extroverted.
In terms of whether it’s better to marry someone similar or different, it can go either way, so there is no rule. It depends what you are comfortable with and what works for you.
Just my opinion.
Hatzlacha in finding your zivug b’karov!