No one at this point knows whether UA will take CO's place in the Sapphire Preferred list of airline partners, but with Chase's close relationship with UA, it's not a bad bet. Until CO goes away in the merger, you can take the bonus points from Chase, transfer them to CO, and then merge them into the Mileage Plus plan. Given the 7% annual bonus on all points earned during the year, effectively making the signup bonus 53,500, and the 2 points/dollar spent on travel and restaurants, the Sapphire Preferred looks like an increasingly good option.

I'm an AA person myself, but that's because AA is a good option out of my airport. I think you've approached this the right way by trying to figure out a plan that meets your travel needs. AA and BA, the Sapphire Preferred's other airline partner, both fly out of JFK. For international travel on BA, you'll have to contend with high fuel surcharges, but I've found good value in using BA miles for international travel in higher classes. Plus, you can book BA flights using AA miles and AA flights with BA miles.

The Chase/Southwest card might also be appealing now since Southwest flies out of LGA and apparently wants to increase their presence at EWR. 50,000 RR points, only a first purchase requirement to earn the miles, and a 6000-point annual bonus that roughly equals the cost of the annual renewal fee make for a pretty good option. With the tight correlation between the cost of flights and the use of RR points, this card offers plenty of opportunities for reducing flight cost on shorter routes. I think it's a nice supplement to the Sapphire Preferred.