Hi Everyone. I thought I would give you an update on how it went.
First, thank you all for your advice. I read and considered everything you said. In the end I decided that I would rather focus on surprising her than the ring. My opinion is that I could always buy a nicer ring but the opportunity and surprise would be once in a lifetime. So, I bought a nice, placeholder ring. We didn't end up getting her finger sized, and by doing so I threw off the scent of what was going to happen as she thought I had given up on the idea because I stopped asking.
So on Dec 31st, just after midnight, when the sky was covered in fireworks, we were standing on the hotel balcony, which overlooked the whole town below, watching the sky catch on fire (I have never seen that many fireworks in my life) and I got down on my knee and proposed. She said YES! I was so excited. It was perfect.
Now, we are going to get her ring sized and I am going to buy her a ring. I am still deciding whether I want her to choose with me or for me to choose for her. They both have their pros and cons. If she comes with me I know she will buy a ring that she loves, so I don't have to worry about making a mess of it, but it will take a lot of the personal feeling of buying her something special away. Anyway, now I am trying to decide how much to spend on an engagement ring when after talking we will most likely actually get married in less than 6 months, but that's another question for another thread. Thanks again, everyone!