Well I need some more SD cards and I forgot them for this trip so what to get for a Sony A7R III. First thing is that they have two different readers. The slot 1 is a UHS-II with up to 300MBps write speed while slot 2 is slower. So use slot 1 for videos or if you are taking bursts that will exceed the internal buffers they have.
For slot 2 you can get away with slower as they only support UHS-1 cards with 90Mbps writes
Some choices are from Brian Smith and The Wire Cutter. The main thing is to be aware of counterfeits. Do not get anything on Amazon which from a third party seller and get it in the original packaging. That should help. You can test your card with CrystalDiskMark to make sure so that’s the good thing about buying from Amazon you can return it. CrystalDiskMark
Some choices for UHS-II Class 10 U3 for slot 2:
1. Sony SF-G128/T1 High Performance 128GB SDXC UHS-II Class 10 U3 Memory Card https://www.amazon.com/dp/B06ZYNNK9H/ref=cm_sw_r_cp_tai_LRFRDb7F9SDPG which is $208. I got one and it is expensive but seems to work well
2. SanDisk 128GB Extreme PRO UHS-II. I’ve used these quite a bit https://www.amazon.com/dp/B01N9JC7ET/ref=cm_sw_r_cp_tai_CXFRDb5HYVFTA
3. Lexar Professional 2000X 128GB SDXC Uhs-II Card https://www.amazon.com/dp/B012PL522W/ref=cm_sw_r_cp_tai_rqGRDbMSRQF3R is the one that Wirecutter liked which is it is 1.5x faster than the Extreme PRO UHS-1 so good for burst. Note that for 4K shooting, the Slot 2 should be fine as UHS-1 should be good enough. It is $160 for 128GB so pretty expensive
Then for slot 2, you can get a UHS-1 card which is way cheaper.
1. SanDisk 64GB Extreme PRO SDXC UHS-I Card – C10, U3, V30, 4K UHD, SD Card – SDSDXXY-064G-GN4IN https://www.amazon.com/dp/B07H9J1YXN/ref=cm_sw_r_cp_tai_bhGRDb29TTGWF is the later model that is 170MBps read vs 90Mbps read, but it is still 90Mbps write.
2. SanDisk 256GB Extreme PRO SDXC UHS-I Card – C10, U3, V30, 4K UHD, SD Card – SDSDXXY-256G-GN4IN https://www.amazon.com/dp/B07H9VX76D/ref=cm_sw_r_cp_tai_tkGRDbN3CFCC7 seems like a better deal given the size. It is just $72 from Amazon for 256GB