It doesn't really matter what you say that much, because she will either find you attractive or she won't. If she does, you won't put her off unless you say something awful, and if she doesn't, then compliments and chat up lines won't change her mind.
I would say establish a bit of eye contact first, if she smiles and seems interested, then approach her. Just say hi and talk to her normally, if you can't think of anything you could comment on how busy/quiet it is in the bar, or ask her how her night out is going so far, stuff like that.
Well you know yourself that you already are taking chances by talking to her. If she is a kind-hearted/down to earth person she will not judge you right on the spot and will listen to what you have to say before interrupting you. From the words "I think..." and on, is great. Its not creepy at all, why do you think she would judge you tho is my question?
It's always gonna make a dorky impression when you say something you've learned by heart beforehand. Why not improvise? Chances that you'll appear less cramped and hence have more success are way higher that way anyways.