This is a tough process, and everyone ends up following the path that suits them the best. For us, we are still waiting to travel to Kazakhstan, and are hoping to travel for two kiddos (although that is a question at this point as the country is changing the rules on us as we speak). We ended up really liking the health care of the children there, and were intrigued by the culture, among several other things of course.
As far as the transracial family issues, all I can say is that there are people out there that will stare or say the wrong thing, but how you deal with it in your home and help these kids get their identity of who they are and what they believe in is all you can do. We have tossed that issue around as well because where we live is not all that diverse culturally. We have come to the conclusion (its a personal call, and we all have to be honest with our hearts on this one), but in our hearts, we are ready to not worry about what the outsiders (others on the street) think or say. Since you are thinking hard on this topic, I would recommend trying to connect with others that are now a part of a transracial family and if they will allow you to be direct, ask them about your questions and concerns as this could help you in your understanding of what to expect (as much as possible).
About the age thing, all I can say is if you want a family, then you should have one. I learned 15 years ago when my brother was killed by a drunk driver that we only get one go, and I would never trade in those 20 short years I got with him for anything in the world. So, its all about quality, not quantity!!! Just my opinion.......
And go to as many seminars as you can!! Even if you don't think you want to go to that country, as these are great places to meet others like yourself, and learn as much as possible about this process!! Good luck!! Keep asking questions!