I don't think anything is available yet. Last we heard AllWinner's order was still being processed by TSMC, rumoured to be 50 million units over the next three years. It would take months for them to be packaged, the SBC to be finalized, assembly, QA etc. And of course AllWinner aren't making these for SBCs, they're making them for their lineup of crappy no brand sub-$100 phones/tablets/smart TVs/etc so the bulk of the chips will end up in those.

At the moment all that's available to order is the HiFive Unmatched, with delivery in "Q4" (this year hopefully!). RIOSLab SBCs (https://rioslab.org/) should be coming next year.

If you want to run RISC-V today, use QEMU: https://fedoraproject.org/wiki/Architectures/RISC-V/Installi...

Quite likely there will be SBCs in a few months with that SoC. Likely in the first quarter of 2021.

The estimate for availability I've seen in the twitter thread is "within 2 month".