Something to look in to, if you go for living in the US is that while the K1 visa process can be faster than the process for a K3 visa, there are some things to bear in mind. First of all, while applying for the K3, you can also apply for a 2 year visa for your spouse while the immigration takes place. This doesn't always get approved, especially if they are beginning processing the actual immigration request (that's what happened to me and my wife).
The second thing to note is that again, I have heard reports of the K1 visa being faster, I have also heard that the number of consular rejections is incredibly higher. You have to show absolutely incontrovertible evidence that you will get married. If you are already married, the evidence is much more heavily in your favor, already, and the proof process is much easier.
I assume this is true for other places as well, but I am speaking from my experience from my wife immigrating to the US from China. When I spoke with an immigration lawyer regarding this, he said the K3 process was the best option, due to the comparitively lower rejection rate, even though the K1 can be faster at times.
Good luck no matter which way you choose!