1) 가비 or 게이비 ( but this name does not give any sense, it looks like a grey building or
someting like a foreign machine )
I recommend 깨비 or 깨비^^ as your nick-name, because It would recall your name, Gabby and it seems unique. 깨비 means a sprite. But it gives an impression of something cute,interesting.
I know that I'm very poor at Enghish.
but, I am sure that you could catch my words...... I hope.....^^;;