Fiancee visa seems the best...

It is complex and will continue to get more and moreso. In short do the research for if you make a mistake it will cost you dearly. I'm not sure but you may need a certain amount of wealth and/or employment opportunity, unless she has a certain amount of wealth.

In short immigration does not want, especially in these horrid times, people who are short on funding. It is becoming a major issue. If she has a house paid for and a good job you might be ok if you are short on funds, or it might not be. Too often males and females marry an American, then once here, eventually divorce, and without skills become a deficit to the already stressed social support system.

I'm not making a judgment but showing you the rationale. I had a long time nursing friend tell me yesterday that she was being sent back to Canada... I had always thought she was an American, but she wasn't. Things are tightening up all around the world and my guess is that it will tighten further over the next few years. So be careful and good luck.