Would something like this be supported?

http://www.ebay.com/itm/SGI-RACKABLE-3U-STORAGE-DAS-SERVER-SE3016-16-HARD-DRIVE-BAY-SAS-SATA-MINI-SAS-/120992146189?pt=US_NAS_Disk_Arrays&hash=item1c2bb1a30d

 

...that's a DAS box with internal SAS expander.

As the seller mentions that it will work with a LSI based HBA, I don't see that much of a risk (based on the price as well).

 

You will need an unRAID box with a SAS HBA, like the IBM M1015 (flashed to IT mode) or similar...plus cables....plus SAS 8087 to 8088 connectors/plug-converter

Thank your for the answers.

 

I thought that would work great for an unraid build, just needed to make sure it wasn't some sort of big no-no

...found this: http://facepunch.com/showthread.php?t=1159763

 

Looks like there are some of these pieces on the market with different configs or at least different advertised features (like support bor 3TB drives or 6GB links).

 

Your seller advertises that all the nice features will work, but as per link your mileage may vary.