I’m surprized that no one mentioned this – or perhaps I just didn’t see it when I was scanning through the replies.
Have you asked your teacher what harp might be best for you? Since you are already taking lessons, I assume that your teacher will be your permanent teacher. I wish that I had found my teacher before my first harp. I’ll always love that harp because it introduced me to harp music, but the tension was way too light for the technique my teacher would teach me.
And I do believe that renting is an excellent way to go at first.