Well I am batting .500
This seemed like a good idea, mSATA slot and one SATA port, but it is too tall:
https://www.newegg.com/Product/Product.aspx?Item=9SIA1JM2CZ0249&cm_re=sedna-_-9SIA1JM2CZ0249-_-Product
This one just barely fit:
Two mSATA SSD. I am running Windows 10 from one of the SSD.
http://sedna-shop.com/index.php?route=product/product&path=60&product_id=70
As both of these use x1 PCIe two SSD's would saturate the