Given that you're about to spend $9500 and assuming your family's credit is good, I would not say that any one card might be necessary. You might consider a combination of a UA and/or CO Chase card (only giving 30,000 miles right now although there is a thread on a targeted CO business card offer for 50K--the big advantage here is only a first purchase is required plus adding an authorized user--your husband--to the account; if you take the CO card, you can transfer directly into United's program), a Chase Sapphire Preferred card with a 50K bonus in Chase's Ultimate Rewards program (these points are directly transferable to the CO FF program at a 1:1 ratio; you could then transfer miles to the UA program), and an Amex Preferred Rewards Gold (similar to the Chase program except it's titled Membership Rewards; similar direct transfer ratio to CO and same transfer to UA).

You and your husband might each be able to qualify for one of these cards, thus doubling the bonus miles earned. Before applying for any cards, I'd look carefully at the details of each card to see the spending requirements so that you could spread your $9500 to get the maximum number of miles. Plus, keep in mind that while some transfers are relatively quick, others are slower so you'll want to start the process of transferring as soon as possible so that you can try to arrange your travel. And since at some times and on some routes, award availability can be sparse, you'll want to have your acquired miles in place ASAP so that you can book your travel for November.