Ok- take a step out of the usual models. Here's something already seen but not exploited properly. Seven port USB hubs are now average $20 from some sources. Flash Drives are Ballpark $10/GB or less size and type variables taken into accoun So using a few cheap drives as sacrificials and expensive ones for semiperm storage we can tailor a composite Flash RAID to our needs. So far we've seen this at various places as a hack. What about a pocket drive case taped to a hub and radiating a few selected drives as needed? Boot from SDA into a Puppy or Damn Small Distro set as TORAM. Don't even mount the Spinning HD of your RAID unless a session needs it! The limits of using this base hybrid are rather awe inspiring. That 200 GB pocket Drive for example.
Imagine a 7 port hub with 6 200 GB drives neatly arctic silvered down IN a laptop cooler plate..
A tiny bit pricey compared to other ways, But 1.TB IN a laptop cooler case seems way dare I say -COOL