RAID Enclosure Recommendation?
 

To spare everyone the details of the system, since I don't think you need them, I'll keep them to a minimum.

I have a Dell Poweredge R310. I need a new RAID enclosure. The R310 is rack mounted, and I'd love something that will also rack mount. I am trying to keep the budget to a minimum, so I would like to spend under $500 on the enclosure. If it's not rack mountable, but is under $500, that's fine.

I'm fairly open to the number of bays in the array, since I'll likely be buying new drives (I have a few 1 & 2TB SATA drives already). In theory, having a lot of space here (6+TB) would be great. I would also love for them to be SATA though (not SCSI).

I know next to nothing about RAID enclosures & arrays, so I'd love any resources as well.

Thanks :)