Well, if we take a few steps back from ever-so-fashionable blogger-bashing, there hasn't been a lot of help here so far. So I'll try my best to suggest the concrete steps you need to take to make your dream come true.

1. Ibleed0range's advice is right on. Forget the spend, well for now, and focus on new credit card sign up bonuses.

2. Your assumption that you need to pay cash for domestic airfares and save miles for international travel is incorrect. In fact, they are different kinds of miles, and you can collect both.

3. A million-dollar question is if your credit file supports multiple applications that we here call app-o-Ramas. If the answer is yes, decide what you and your wife are comfortable with. You don't have to go all or nothing.

4. Another million dollar question is if you can meet spending requirements (which can be from $1K to $5K in 3-6 months) without some tricks that you would need to learn first. This too should dictate how far and how fast you go.

Hope it helps.