Hi Charlie
This is what I use below for my gear safety ("squat") switch). The AS-1 for $45. It looks like a minature plastic microswitch  (about 2"x1x1/2") Small and light. I also use another one to operate the TCW two speed safety trim module.   I would guess that the deadband (range between open & closing) is about 10kts or so, which isn't bad.  Works great, and I've not had any issues with these switches over about 500hrs.


http://www.tcwtech.com/index.htm

Regards
Clark mobile: +44 7557 804 630