How many cards in the last 24 months? If you have less than five personal cards opened in the last 24 months I’d go with the Southwest cards.
In December 2018 I would apply then for two Southwest cards. Don’t spend anything on the card until January. If you get 110,000 Rapid Rewards Points in a calandar year you would get a companion pass for the year it was earned and the following year. Meaning you can designate someone as your companion and they would fly for free with you through 2019/2020.
Currently the Business card is offering a bonus of 60,000 points and the personal cards are offering 40,000 each but this frequently is as high as 50,000 and even was at 60,000 each for a bit. The bonus plus the spend requirement should get you close to that 110,000 points and potentially over depending on the bonus at the time. Southwest may also be releasing a premium card that you should consider too.
If you are going for both personal cards then they must be applied for and approved on the same day.
If you are going for the buisness card that application has to be done before the personal unless you want to wait 30 days between your applications.
If you want a card now I would consider the Chase Sapphire cards but make sure you don’t go over 5/24 so you can get that companion pass for your 2019/2020 trips.
Also, you can use your points and your companion can still fly for free. Idk where you are located, but 110,000 points should cover most of the flights. You can go to Southwest website and price out the route to see approximately how many points you would need.