Thanks for all the thoughts everyone.

Ok, I think if both of us get the Southwest Airlines card and a Delta Amex card, we can probably go for around $900. (Using the SW card to fly to NYC or Chi for free using the 50K points and the 30K from Amex to knock $300 off a Delta flight).

I need to further research into the United Card and see if the 40K can be used even if it doesn't cover the entire flight(s) and how much it would cover.