if you all want more robustness then you'd have to use this casing -





This one can support a more robust mobo with 1 PCI slot for you to use.
HDD: 1x3.5” +1x2.5’’standard hard drive bay
ODD: A slim slot-loading optical drive
Extension Function: equipped with 1xsmall PCI
Front Interface: 2 USB + Multi-Card Reader
Cooling Devices: 1*80 x 80 x25mm fan
Dimension: 240*250*100(L x W x H)
Power Supply: optional build in DC power
Remote Controller: Optional the MCE remote control built-in IR receiver
Net Weight: 2.4KG
Slightly more - $179
Initial feedback from Dr_D with the mac mini one is that there is some problems with the alignment of the slot drive with my sample piece -
I will have to wait for more information/review from him to rectify all the problems with the manufacturer.
I've found a supplier for Panasonic UJ-875A SATA Slot in DVD Burner and also pico psu.
I'm trying to fit the entire casing + ODD + PSU for under $300.
That will be the bench mark that I've set to sell the bundle.