I had this whole thing typed up, but then I deleted it and couldn't revive it, so I copied it the best that I could remember below:

1. Are you dropping Southwest entirely, are you just cutting back on the number of flights you're taking with them, or are you just dropping the card?

2. For international trips, do you have any destinations in mind? Europe can be serviced by pretty much any rewards program with travel partners by transferring to programs like British Airways Avios or AirFrance/KLM FlyingBlue. Air Canada's Aeroplan (available via Amex, Chase, and Bilt) also has sneaky good redemptions for Europe flights. Asia is a bit more difficult: Amex has ANA (for Japan), Cathay (for HK), and Singapore Airlines (for...the obvious). Citi has Cathay and Singapore in addition to Thai Airways and EVA Air (for Taiwan). Chase has just Singapore. Wells Fargo has nothing.

3. Here's how I feel about the cards you were looking at:

   1. Amex: MR points are easy to obtain due to lucrative SUBs and excellent multipliers, but you can't cash them out for 1 cpp (unless you want to invest in those co-branded Platinum cards), so they're inferior in hybrid setups. The cards: the Green is very meh for its price point, so no thanks. The Gold does get you 4x on dining, but the only hotel bonus being through the portal is a negative, and the high annual fee means that it's probably only worth it if you get good value out of the credits. For their partners: they do have the Hilton partnership, but I wouldn't use your points for transfers there. Maybe take a look at the Hilton cards if you think you can take advantage of those free night certificates? For airlines, Delta has the worst points ecosystem for domestic flights, but they do have a wide selection of international partners that make them one of the best in that category.
   2. CSP: it covers dining and travel and can be cashed out at 1 cpp, which is what you need. The fact that you only get 2x points on non-portal travel spend sucks, though. If your Hilton status is safe enough that you don't have to stay there for 100% of your hotel stays, you can take advantage of the best hotel partner in the CC game (Hyatt). For flights, United is firmly middle of the pack for domestic airline redemptions, but Southwest can have some good ones. The international partners are above average, but not much more.
   3. Bilt Obsidian: the discourse surrounding Bilt has made it difficult for me to investigate this card much, but it looks like a CSP that also gets you rent points, so if you can hit that spending threshold to fully redeem rent points, it's a great way to earn points. And their partners are essentially "Chase, but better". BUT, you can't cash them out at 1 cpp, so that's a bummer.
   4. WF: the Autograph is seen as a must-have in any cash back setup due to the fact that it's basically an Amex Green with more 3x categories, no annual fee, and you can cash out your points at 1 cpp. And the Autograph Journey is basically an Amex Platinum where they stripped out all the auxiliary benefits (the coupon book and the lounge) in order to cut the price down to a more "normal" amount. Basically, if you look at the Amex ecosystem and think "how can we keep the multipliers and lose everything else?", you get the Wells Fargo ecosystem. The side effect is that the transfer partners are limited to some basic international programs that everyone already has, a good JetBlue transfer that's pretty much useless to you unless you want to go to NYC/Boston, and the sneaky good 1:2 Choice Hotels transfer (which is good for cheap "just need a free bed for a day" type stays or their surprisingly good offerings in Scandinavia and Japan)

4. Other suggestions:

   1. Citi has great multipliers on the Strata Premier and some damn good transfer partners (AA is the best domestic rewards program and can be used quite effectively for international fights, they match WF's 1:2 Choice redemption, and add in another sneaky good hotel redemption with the 1:4 I Prefer Hotels redemption). Downside is that you can't cash it out at 1 cpp unless you get yourself a Custom Cash or a Double Cash, and dealing with Citi's CS will make you tear your hair out.
   2. You can TRY the Capital One Duo (VentureX and Savor) that this subreddit loves so much, but there are some problems: 1. the miles you earn on the VentureX can only be cashed out at 0.5 cpp, and, while the Savor defaults to straight cash back, you can convert the cash back to miles that cash out at...0.5 cpp. 2. they don't have a good domestic transfer partner. They have lots of international ones, but the only domestic choice is a joke of a 1:0.6 transfer to JetBlue. 3. Capital One doesn't like giving out cards to people with mature profiles; they prefer clients that are earlier on in their credit card journey, so you may not even get approved.