RE: Inexpensive and reliable onboard glow system.
I prefer to use C. Brent Dane's Optoglo or Optoglo II to optically isolate the on board glo driver. On some planes (with fixed gear) I use it on the landing gear channel and use the landing gear switch to turn the glo on or off. On other planes, I use it on the throttle channel. Both versions of the Optoglo have a trim pot on the board that allows you to adjust the set point where the glo driver comes on (i.e. glo comes on at or below 1/4 throttle; once you exceed 1/4 throttle, the glo driver turns off). Fairly simple to make and not very expensive either...
[link=http://www.cliftech.com/pdf/Optoglo.pdf]Optoglo[/link]
[link=http://www.cliftech.com/pdf/OptogloII.pdf]Optoglo II[/link]