Here we go again!
Put in the loudest, most obnotious horn you can find. Install a switch on the throttle so it activates whenever the throttle is at idle. Wire another switch so it opens only when the nose gear is down, locked, and overcenter.
Now wire these switches into the LOUD horn. The horn will go off whenever the throttle is at idle, and the gear is not down and locked.
A light is not enough, and small buzzer is not enough.
You'll be looking at the light, kind of wondering why its on, just as the nose settles to the runway, and skids to a stop. (been there, done that, got a "T" shirt)
The sound of the horn must override everything else, I could be on fire, or have a passanger screaming and puking, but when that horn goes off, It gets my immediate attention.
Oh yah, Did I mention that the horn needs to be VERY LOUD.
If you do not install this type of warning system, I am so convinced that you'll do a gear up within the first 1000 hours, I'll put $100 on it.
Ok, All those that "HAVE" send me my money.
Waiter