I don't even understand why you are writing to women on marriage sites.
If you want to move to Ukraine, just do it. Once you are there, pick and choose the one that want to marry. If you are already in the country, she will not have the expectation that you will be taking her back to the USA right away. This will quickly weed out the ones that are looking to get out of the country. If that's her intention she will move on to a more suitable target. If she she sticks around then it will give you some degree of assurance that she is not out for a passport.
If you want to move to Ukraine, just do it. Once you are there, pick and choose the one that want to marry. If you are already in the country, she will not have the expectation that you will be taking her back to the USA right away. This will quickly weed out the ones that are looking to get out of the country. If that's her intention she will move on to a more suitable target. If she she sticks around then it will give you some degree of assurance that she is not out for a passport.