You got the new camera body, and now all of your media card collections may not be completely usable.

If you are shooting large files and/or video, you definitely need to change it up, and upgrade. Speed is the name of the game.

Kinda why you changed to the new cameras, correct?

Before you consider your options, remember that we have gone from CF cards, in the beginning of digital to SD UHS-I cards, to UHS-II cards, and all of the capacity and speeds that those cards could be manufactured with.
Now, after trying a few other formats for high speed (like the failed XQD format), high capacity media card, the imaging industry seems to have come to the conclusion that CFExpress cards are what we need.

Have to agree.
To take advantage of the newer video capabilities and 40MP plus stills files, you need a media card that can handle it.
Here is a size comparison:

If you are shooting on continuous, like for sports, and need to capture RAW files with fast read/write capability so you don’t get locked out of wait for the card to do its business CF Express is the way to go.

Different camera companies had published preferred cards for their cameras, and I find it’s always a good place to start
Like Fuji
Heck, they did the testing!

You will need a new card reader as well.

Delkin has bundled some of the cards with a dual card reader for SD and CFExpress B

ProGrade makes a dual card reader as well.

Hot tip is that I use a few of these cards readers, plugged into a multi data port hub, to download/ingest concurrently to Photo Mechanic. 
Trying to cut the workflow time, wherever I can.

For now, I am using the 2-slot combo of an USH II and CFExpress B, as recommended for my current cameras, Fuji X-H series.

Now, Sony has gone with the CFExpress A format, with their reasoning explained to me as it will fit into a SD media card slot.
And of course, they recco the Sony line of media cards.
Duh.

I guess you then have an option of 2 SD cards, or SD + CFExpress, although the CFExpress B’s seem to be the faster card.

Trust me when I tell you, if you are shooting the large MP stills or 4-8k video, you want the fastest cards you can get.
You knew that.

As far as the brands go, it is up to you. There are some cards I’ve used that have failed, and there are some companies that do what is called “white labeling” meaning trusted media card manufacture’s supply the companies with their product that can get a label added.

For the Fujifilm H2, which has a 2 slot system, I use a variety of SD USH II cards (Sandisk, PNY, SONY, Lexar, OWC, Fuji)
On the CF Express side, I use a few: Delkin Power, Manfrotto, and if I’m shooting video Delkin Black

It does also depend on your budget, of course, and end of years sales on media cards are my usual purchase. The prices are generally heavily discounted, so best time to load up.

I know, we all have a ton of media cards that may not keep up with the new cameras.
Keeping CFEXpress back-ups, and cards for multiple bodies, ainlt cheap, but…..

Adapt, shrug it off, and upgrade the easiest and critical part of your content creation process.
I also like this breakdown by Shuttermuse