If they've got the credit I'd apply for the OnePass Plus card (
http://www.continental.com/web/en-US...x?offer=OPP40K) for 25K points each (it says 40K but really likely that it will only be 25K) and also the MileagePlus Explorer card (
https://www.chase.com/online/Credit-Cards/united.htm) if you can find a good sign-up bonus there, too.
The CO and UA accounts will be merged at the end of the year so all those points will end up in a single account for each of them.