SATA RAID Enclosure w/ Temperature Monitoring?

vanyel asks: "Yesterday, my external USB 2.0 drive enclosure finished cooking a 3/4 full 200G drive after its fan quit working who knows how long ago. In the time honored tradition of closing the barn door *after* the horse has wandered away, I'm accelerating my quest for a RAID solution. In particular, I want something that will support 4 SATA drives and has temperature monitoring that doesn't require a particular vendor's RAID card or Windows. Better yet, is there a RAID-5 NAS that isn't in the $4-5000USD price range. Anyone with a better barn door to close this problem with?"