Hey Razor,
About any coal, charcoal(charred wood and coal), natural wood charcoal or coke will do the job.
The big thing is they only get really hot when you add extra oxygen and some of them contain more impurities like sulfur than others.
Coke is the best if you can get it. Last longer, gets hotter and the impurities have been burnt out of the coal.
Plain coal burns hot and last well, but can have a lot of impurities.
Charcoal last longer than natural wood charcoal, but contains more impurities because of the coal content.
Natural wood charcoal burns hotter and contains less impurities than charcoal, but burns up a lot faster.
But high quality charcoal or natural wood charcoal like Steve mentioned works fine. Just blow air over it and they will all get plenty hot enough. Some of of the cheap brands contain a lot of sulfur that can cause some problems, so I might stay away from them and soft coal.
Hope that helps.