Regarding the U.S. woman, be VERY "open minded" and welcoming in attitude with her. If you go into it looking for flaws or negatives, you will surely find them. That includes physical flaws. The better approach is to take is to watch for anything that you absolutely could NOT get past for a lifetime, and those things should be based on what is "essential", NOT preferable. No one is going to come along that satisfies your every desire. Is she a good woman who will make a good wife and mother? Are you attracted to her physically enough (it does not have to be blissfully right away, because that can happen as you fall in love over time)? Does she believe the teachings of the Church and seek to practice them (a desire to become a saint and get to heaven)? Is she kind and forgiving? Does she seem easy to get along with (not a high-maintenance type of person)? Is she a consistent person (does not change into someone else when around certain people and then back again when alone with you — this one is tested around family and friends)? And as for anything physical about her you find to be flawed or unattractive, first look in the mirror (not just your face, but your whole body) and consider that someone has to accept your physical flaws as well. It will help you stay humble. This goes for your own personality and behavior flaws as well. Consider them first, and it will help you to NOT be so quick to discount her (or any woman, for that matter).
You need to go into meeting women with the realization that they will fail you in moments because they are NOT your savior, nor are they responsible for your complete happiness. You are looking the person you want to "DECIDE" to give yourself to in order to make HER happy and the children that are given to you. That is the meaning of your vocation to marry. Now, if you are a wise person in making your choice, you will make sure you learn enough to know that she is a person who understands that this is her calling to you as well. That way you won't be stuck with someone that you have to do all the giving for, and get nothing in return.
Everything else can pretty much be worked out (hobbies, interests, personality traits, baggage from the past, bad habits, moments of weakness, etc.).
The institution of Holy Matrimony is a very "practical" vocation. It is not primarily about romance and attraction. It is about being "suitable" for marriage and being "evenly yoked" for the purposes of marriage that God has designed. You want someone you can really share your life with, and yourself with. To consider beauty primarily is to condemn yourself to a near future that is empty due to problems you never foresaw that have to do with fleeting looks and cultural barriers, or anything else that got swept under the rug during the consideration and decision process.
God is looking for men and women who are ready to give up their self-centered concerns for the role of self-donation and giving, who will be open to life, who will make their decision a permanent one for life, and who will be totally faithful to that one person in mind and body and heart, as well as be focused on the care and needs of the other and the children before themselves. People who want to bear fruit for God's glory and the population of heaven and earth. People who see love as a giving to another, not a wanting to get from another.
This all points back to the U.S. woman, or women like her, being the wiser investment of your time and efforts rather than foreign women. I realize men are looking for certain qualities in women that they seem to feel they are NOT finding in American women. Perhaps that is something American women need to learn about men and make changes accordingly. But men are also deceiving themselves in thinking that foreign women are more humble, and quiet, and holy, and willing to dote over their man's every need, and modest in dress, and don't care about large age differences, and are more physically attractive (in an exotic sort of way). I have been to many South American countries and I can tell you firsthand that secularism, consumerism, and materialism have all entered into those societies and are affecting the Catholics there as well. Just as in America, not ALL are affected. But the dream world that these women are somehow less tainted is just not true. The problems in men and women are worldwide. I think it is better to stick with your own territory and what is most familiar to you. It gives you much better chance of success in marriage. There are men who successfully meet and marry a foreign woman from Central or South America, or the Philippines, or a place like that (we are not here talking about British or Australian and the like), so I don't want to sound "absolute". But I do think there are many, many Catholic men out there who are looking at these other countries for a woman because they have found American women they have met (even Catholics) to be unattractive in their "ways", and that affects their ability to be attracted to them physically. But again, I think in a lot of cases, they are not looking at the big picture. Culture, language, and many other factors do make a difference in the long run. It is best not to allow yourself to be easily "turned off" by women in the U.S. because of a "dream" of how it might be with a foreign woman.