Ron - Your solution looks pretty good as long as the -6 bypass hose provides enough volume that your engine doesn't have any hotspots.. Do you have any issues with blowing too much coolant into the recovery tank?
Ant - I like your mods! very nice...
Bill - I'm not sure that my proposed solution is much different or more complex than what you've suggested.
I'm attaching some pictures below that show the mocked up system.
The first picture is of the BMW-2002 80c Thermostat. Cost - $15
This is a mile-high view of the whole system mocked up with pipe-insulation in place of actual pipes/tubing. The bottom tube traversing to the rear of the car is the HOT tube.
Y-Pipe where the Bypassed coolant will dump into the exit side of the radiator and therefore into the waterpump's inlet.
Closeup of the Thermostat - My cousin is TIG welding a piece of tubing to it that will cause the exit of the bypass to be straight rather than canted at an angle.
About the Davies Craig units -
From what I have found they only flow 20 GPM. Since that's less than a standard mechanical pump (I'm told that's 30 GPM) I thought it to be insufficient.
I'll be the first to admit that I've never yet used a remote water pump before. I'm not cast in stone in my plans and open to what others may be doing as well..