Dining is easy, as any credit card registered to the account will work, regardless of name. The big fly in the ointment is that one only earns fewer miles until they become "elite" diners (11 dines) and then it's still only five miles per dollar spent (including tips and taxes). The bonus allowing one 300 bonus miles per $30 spent (essentially 15 miles per dollar spent) just ended last week.

Do read the thread clacko has referred you to; might give you some other ideas.

I think it's going to be challenging to get this done in time for a summer vacation, unless you mean 2012.