Raspberry Pi motherboard. This should be model 3B. There is no reason to get an older model. B indicates the presence of an Ethernet connector (RJ45).
Power brick, 5V 2.5A, micro USB connector. We'll need a new one; the one that came with the Pine64 provides 2A, suitable for older Raspberry Pi but not this one.
Case. A clear case is more cool.
SD card. Let's get 32Gb; no reason to get smaller. Look for one with a fast speed rating. I don't know how fast the RPi can go, but a slow card can make the rest of the machine disappointing, as with Mica.
I would like an antenna for Wi-Fi and Bluetooth. This will take some searching. Reviewer says the onboard antenna works. Presumably it is shared between both services.
I would also like a realtime clock.
I should look at the packaged kit, only if they have everything I want.
FBA means sold by the listed vendor, fulfilled by Amazon.
Vilros Raspberry Pi 3 Kit with Clear Case and 2.5A Power Supply.
$49.99, sold by Prestige Milano, FBA.
Contents: RPi 3B motherboard, wall wart 2.5A (with inline pins, not best), 2 heat sinks, clear case (antenna on top?) One reviewer mentions for the SD card the Samsung 32Gb 95Mb/s (U1) EVO Select. Several reviewers mention needing to fiddle to get the board to fit into the case. Reviews are generally positive: 89% 5*, 7% 4*, 4% lower.
Raspberry Pi 3 Model B Motherboard
$36.42, sold by Landzo, FBA.
Just the board.
One reviewer reports
Wi-Fi is decent on the device but not amazing. You
can't expect high throughput from an embedded Wi-Fi chip without an external
antenna. Implying that it at least works with the onboard antenna.
CanaKit Raspberry Pi 3 Complete Starter Kit - Includes 32 GB Samsung EVO+
$69.99, sold by CanaKit, FBA
In the kit: Black case, 2.5A wall wart, Samsung EVO+ U-1 32Gb SD card (this is the one I wanted to get), itty-bitty card reader freebie, 2 heat sinks, HDMI cable, motherboard (made in UK, not PRC). Reasons for jimc to get a different kit: I prefer the clear case; I don't need a HDMI cable.
CanaKit Raspberry Pi 3 Kit with Clear Case and 2.5A Power Supply
$49.99, sold by CanaKit, FBA
In the kit: clear case, 2.5A wall wart, 2 heat sinks,motherboard (doesn't say country of origin but their policy is to use UK, not PRC). Reviewer Bobcat warns that the onboard Wi-Fi/Bluetooth antenna is on the underside of the board and a rib inside the case can press on it and break it if you're not careful during assembly.
Samsung 32GB 95MB/s (U1) MicroSD EVO Select Memory Card with Adapter (MB-ME32GA/AM)
$11.99 SBSF Amazon
Micro SDHC card and full-size adapter. 32Gb. Up to 95Mb/s read, 20Mb/s write, class 10 or UHS-1. Product hype: resists 72 hours in seawater (IPX7), operating temp -25-+85C, radiation resistance 50 R (0.5 Sievert = J/Kg), magnetic field 15T (tesla) (irrelevant), Tidbit: $150 for the 256Gb card.