The eagle has landed.
ONDA D1800 BTC with integrated Celeron bare bones -- under 100 USD.
The seller is from taobao and usually Mandarin speaking so I have no head or tails on how to order.
[...]
3 x sata and 3 x 4-pin molex ..... how do to make this work .... with a 1200w HP server PSU, PICO and BB solution

Wow! Hope that at least some of the BIOS is not in Mandarin

As for the 1200W server PSU with Pico... I think you going to need to wire up all of those extra molex connectors labeled as POUT# on the motherboard. Just by looking at the width of the copper traces on the board that lead to the connectors, I can tell they were planning on using those as power inputs, not power outputs (POUT?).
I will try the P106 first since they may work without additional power.
Lots of testing on this board.
I dont intend to mess with the BIOS, and just plug in the USB stick with smOS.... and see what comes up.
If this truly a BTC board - it should work out of the box like the Asrock H81.