I think the pieces are all in place (with a little modification) for a really cool self-contained add on wcing kit. Think about the combination of 1 pass 120mm fan radiators, an DDC/MCP350 pump or the little C-Systems unit, and the Swiftech MCR120 radbox kit and passthrough. Now put them all in a blender and make them into one unit:
Make a fillpoint on the top tank of the rad. Use the rad as the reservoir/fill point.
Use a modification of the MCP350 that puts an inlet at 90 degrees from the pump (I know I've seen people do this on forums and maybe even some German mfgr sells pumps like this? Couple pump inlet to bottom of the radiator tank. Now you just bolt the radiator box to the case, connect tubing through a PCI-slot to the wbs inside and connect power to the pump and the 120mm exhaust fan. You have a cooling kit that'll fit on any system, could be molded as a single unit, would cool well, and should never have issues with air in the radiator or pump running dry or anything like that. Am I missing something here?
The only things that leap to mind are: (a) Making sure proper size for bottom tank to get pump necessary liquid (b) Making sure proper size/geom for top tank to fill it (c) some practical considerations such as do you make custom rads with tanks of metal, or do you make the tanks of molded plastic and mate them to the rads somehow? Molding presents some pretty clear advantages (the point to observe water level would be easy then, you could mold the return line for the top tank etc etc) but it would be expensive.
Am I totally off base here, or would this be a really nice way to wc sff systems and compete nicely with Koolance-style boxes?