Check this MB for mining... No need for Risers

It comes with Built in CPU.

Take so-dimm DDR3

That saves a bit of cash. No need risers that is a good chunk also.

Fans for MINING

There are a few boards like this such as Colorful’s C.B250A-BTC PLUS V20, C.J1900A-BTC PLUS V20, Onda D1800.

The fact that it does not support consumer GPUs and only special mining GPUs is a very big minus because it takes away the ability to sell off the consumer GPUs in case the profitability of mining drops.
Also, as the difficulty increases the specific mining gpus will become obsolete.
In the case where you can use consumer GPUs, you can just sell them off and use this cash + the some funds from mining profits to buy the latest consumer GPUs that have higher hashrates.

I wonder how they can limit it to those GPUs, how would the board know? Or do they have something in the firmware that blocks it? There is no talk about what software etc is used, can I load my own Windows OS?