Hi BJ
Glowplugs have been changing recently, as the expensive metals used in the elements become more expensive - they don't seem to last nearly as long (but that's another topic)
There are few "idle bar" (the bit of rod across the bottom) about these days as a 'standard' plug should be enough to deal with all but the very slowest revs.
For general use with 10% nitro, you should be looking for a medium/cool plug (the higher the nitro used, the 'colder' the plug needs to be).
Something like the Jen 4 from Just engines -
http://www.justengines.co.uk/acatalog/Glow_Plugs.htmlof the latest generation of Maxflash from Model Technics (order from your usual fuel supplier)
http://www.modeltechnics.com/glowplug.htmYour local shop might also have some old stock of Firepower (F5) which are another possibility.
Cheers
Danny