After extensive research on the Internet, I discovered that there are only a few quadrants available that strive to replicate a genuine 737 throttle quadrant.
Revolution-Sim, a company in France appears to produce an exceptionally well designed quadrant, however, not with an inexpensive price tag. ThrottleTec also produce a very good intermediate throttle quadrant that is reasonable priced, however, doesn't really replicate a genuine throttle.
After more research and considerably thinking, I have found a real 737 series throttle quadrant from an aircraft scrapped in a tear down yard.
If I manage to aquire this TQ, I will have the internal mechanisms refurbished and retrofitted to work with flight simulator using a SYS board and phidgets.
The throttle will not be motorized as this level of functionality I have been lead to believe involves a level of functionality that can cause issues. Further, many of the issues that people have with throttles revolve around their use in motorized / automation mode. I like to fly manually, so non motorised suits me.
I must confess that the feel of a real throttle in your hand leads no limit to the imagination!
It's early days yet, but I'm very hopeful I will be purchasing the unit.