re: Rewards credit cards...which one to go with

Since you went with Southwest (presumably for the 50K signup bonus) you should also get the business card for another 50K bonus when the bonus goes back up to 50K (just keep an eye out for when it moves back up). The reason for this is sign up bonus counts towards the 110,000 point companion pass which allows a companion to fly free the rest of this year and all of next. You can change companions up to 3 times. I signed up for the personal and business card on the same day and got approved for both. So I got 100,000 points plus the 4,000 points I got for the minimum spend. I transferred Hyatt points (5000 Hyatt = 2400 southwest points) to get to the 110,000 requirement. Now I can use the companion pass an unlimited amount of times the rest of this year and all of next. Just something to keep in mind.

The other best cards right now are the Chase Sapphire Preferred and the Chase Ink Bold / Chase Ink Plus business cards.

You don't have to have a business to get the business cards. Just use your social in the tax id number. I won't get into the ethics of that but I know a bunch of people do it and just say they have a consulting business.