a1 II has two CFexpress Type-A / SD card slots. So the best choice is to get two CFexpress Type-A cards. I recommend the Lexar Silver Series CFexpress Type-A cards. https://www.bhphotovideo.com/c/search?Ntt=Lexar+Professional+CFexpress+Compatible+LCAEXSL160G+RNENG&BI=8941&KBID=10361&SID=12345&DFF=d50

Honestly, I tend to play it safe when it comes to storage for a body as expensive as the a1 II. Compatibility is the biggest headache with these new cameras sometimes. I would look into the Nextorage NX-A1PRO 640GB CFexpress Type A because they use the same tech standards as Sony's own stuff but usually at a better price point. Reliability is key here... you really want something with VPG-400 certification. That VPG-400 rating is basically a guarantee that the write speed wont dip below 400MB/s, which is what you need for the high-bitrate 8K video modes without the camera throwing an error. Another solid but overlooked option is the Exascend Essential CFexpress Type A 480GB. They've been making high-end cinema storage for a while and their thermal management is excellent. Heat is usually the biggest killer of performance during long bursts, so getting a card that handles it well is a smart move for your workflow. Just make sure whatever you grab is officially rated for those high bitrates so you dont run into issues in the middle of a shoot.

Sony Tough G CFexpress Type A and Lexar CFexpress Type A Gold are both great choices.

Totally agree with the VPG-400 point! @Reply #9 - good point! You really dont want to skimp on cards when youre dropping that much on an a1 II body. If youre looking for something outside the usual Sony or Lexar stuff, I love these:

• Angelbird AV PRO CFexpress Type A 1TB
• Pergear CFexpress Type A 520GB The Angelbird is incredible for huge storage needs! I've been using it and its been fantastic for 8K video... stays cool and handles everything. The Pergear is also amazing value and has been super reliable for me so far. Definitely worth a look if you want more bang for your buck!

For the Sony a1 II, the Sony TOUGH CFexpress Type A cards are a top choice, especially the CEA-G320T or CEA-G640T models. These cards are built for high-speed workflows, supporting 4K/8K video and burst shooting. However, check if your card is part of the batches affected by low-temperature write failures (below -10°C). Sony offers free repairs until 2029 for impacted cards. If you shoot in extreme conditions, pair this with a secondary SD card for backup.

Any CFexpress Type A cards are recommended.

Lexar Silver CF-A card.

The OWC Atlas Pro series is a popular choice. Also consider fast UHS-II SD cards like the SanDisk Extreme PRO line as a more budget-friendly option.

Consider CFexpress Type A cards like the Sony TOUGH CEA-G320T or CEA-G640T models.

I use the Lexar CFexpress Type A Gold. Works well and very fast.