http://www.techpowerup.com/203268/swiftech-releases-the-h220-x-cpu-liquid-cooling-kit.html
 
A dual 120 mm copper radiator coupled to an enthusiast grade pump and water-block.

I'm sure yours is a pretty unique situation as I'm sure most people have their computer inside. Could always assume it behaves essentially like water and freezes at normal water temps. Might be a bit conservative but it's starting point. Out of curiosity what kind of rated low temps have you found?

It should be a lot better overall. The components are the same as what they offer for a custom loop: Swiftech Apogee XL, mcp50x pump, 240mm rad with a modified maelstrom reservoir.

Looks great and I like the performance; not to mention the simplicity of a all-in-one loop.  I don't know how to think about the reservoir and pump hanging off it, potentially covering any RAM underneath.  It all depends on the motherboard layout and where the rad is positioned in the case.  I guess the RAM would still get decent airflow.
 
I wonder if this is their solution to avoid any patent issues.