If you hand start your engine then a glow stick that you show above is good. I like the short ones as they are less likely to fall off.

If you use a 12 volt starter a 'powerpanel' like this http://www.hobbytown.com/Shop/Hobbic...ower-Panel-II/ mounted in a flight box provides a 1.5 volt supply and you can see that the glowplug is drawing power on the meter.

Sport flying I might use a glow stick as I almost always hand start my engines. For competition use I would always use a 12 volt starter and flight box with a powerpanel.