I personally take Islam as it says in Quran. I dont take Hadith and other things very seriously. So I would look in Quran for your question.
As far as i know, Quran doesnt say anything about getting parents permission about marriage. That doesnt mean you shouldnt care about their oppinion. Quran says be respectful to your parents. So of course ask for their permission as a sign of respect and to keep the traditions. But if they say no, you should still get marry. Because parents arent always right and you cant risk your future based on what your parents think.
Finally, be respectful to them and ask for their permission. But dont feel obligated to do whatever they want you to do.
If you ask to any kind of Sheik, he will say you shouldnt get marry if your family doesnt allow you to. But i personally stick with Quran, instead of Sheiks or Hodjas.