Been looking for these too (as well as other options).
I already have a donor set of hubs from a ProII/Arch EX 9er wheelset I have and I’ve been quoted £340 for a service and rebuild using Velocity Dually 650B rims.
I’ve been in touch with Hotlines and promptly received the following:
“We’re expecting the i29 and i35 rims to arrive with us at the end of November and be with dealers at the start of December. UK RRP will be £59.99”
So, I’ll be waiting for these to be available before commencing my Solaris B+ wheel build. They should also reduce the price drastically too by £30-£40 quid per wheel.