Lot of good advice on this thread--but, IMHO, a little overthinking about which cards to apply for.
OP and fiance should have applied for AA 75Ks times three (each) YESTERDAY. No reason to wait to get going on these terrific offers and go to Europe in F. But, you need a little time to do the spend.
Once OP has the miles, no doubt, he will find a nice way to use them.
I certainly have.

Thanks FTers for educating me. ^