I took a look on HobbyKing's website and I was surprised in that they were not selling glow plugs. Most unusual, they sell everything else.
You would think that someone inChina was making glow plugs.
I see they have quite a few hobby shops inEgypt, it might be easier to just buy from them.
for example:
http://www.hobby25.com/
or
http://www.rchobby-egypt.com/