Garters separate the head from the lower part of the body, and some have thicker heads thsn others …. anyway, a tie fulfills the minimum requirement.
A bigger question is – if you have zechus to belong to a menorah focused on intellectual achievements – why do you suddenly care about adding a string around your waist? You don’t feel frum enough because someone else doing something you don’t? Maybe look up some minhagim of say Rav Salanter or Alter from Slobodka, I am sure you’ll find some middos you can still work on. But maybe a belt is an easier path to feeling frum.