you're about there. since its going to be your first time with the method use 2.5 as you get more comfortable with the technique you can cut your strip thinner if you like.
some people use elmers glue to adhere the backside of the binding before SITD. i used to use glue and still do from time to time.
lately i've been using fusible thread in the bobbin and i like doing it this way better.
then when i do the SITD from the front i use regular thread in the bobbin.