SAS Expanders for DIY JBOD Arrays

I do not know about the MD1000, but probably they will be using some custom-made PCBs to have an expander run without a mainboard.

The SAS expanders usually will need the mainboard / PCIe slot for power supply only, so theoretically, you could use any mainboard, even without a CPU. There is this rather well documented DIY-JBOD project where an industrial PCIe PCMIG backplane (originally used for slotting SBCs but obviously providing power to any PCIe card) has been used instead of a full board:

I would look on a HP sas expander, works great

Q: How do I install the HP SAS Expander and what are the power requirements?

A: The card needs an x4 PCIe slot on a motherboard and draws 11 watts of power. The card doesn't require software drivers, it is invisible to the operating system and motherboard. A common dilemma is people needing to use this card in an empty chassis like a Norco RPC-4220 to create a JBOD enclosure. Some people have resorted to using an old motherboard serve as a power source and ON/OFF switch for the chassis - such a solution costs significantly less than buying a prefab expander chassis. Unfortunately this card has no external 4-pin Molex power connector like the Intel RES2SV240, another highly recommended SAS expander card, but in exchange you're getting 36 ports instead of 24 on the Intel

Source: http://hardforum.com/showthread.php?t=1484614

I've just put together a chenbro RM31616 setup which uses a sas expander linked to an LSI raid card. The sas expander is pci form factor but uses the pci slot just for physical stability, ie, all the motherboard interfacing is done via the raid card.

I don't know if that helps you at all.