Hey Bruno,
If in doubt which hostel type you will like, I would start with the more quiet, backpacker-type one. In this case, it is Hostel One. If it is too quiet, you should go for the party hostel next time. Simple as that. You can also just book one night first, and see how it goes.
However, depending on the season you are traveling, beds can be sold out fast. For March you should be fine, since it is not high season. So; I would recommend to go with Hostel One for 1 or 2 nights, and see how you like it.
Enjoy Budapest and let me know if you need anything,
Matt