Question:
With the utmost importance of saftey in mind i wish to know what would be the best type of fire extinguisher ( C02, WATER, FOAM, POWDER, HALON)to have in a lab that makes pyrotechnic compositions?

Answer: I'm sure this one will get a lot of varying responses. As far as a home lab, since you are obviously safety minded to begin with, I would say an ABC for all fires with a little twist. The twist is, use only enough material that, if ignited, will burn itself out harmlessly, an extinguisher might only spread the fire. If you have anything bigger than a harmless bench fire, call the professionals. I have a HazMat CDL (hazardous materials commercial driver's license) and a driver is told to use an ABC extinguisher to keep minor truck fires from spreading to the cargo _if_possible_. They are otherwise instructed to get the shipping papers and get the hell out of Dodge so that they don't make matters worse. Firemen are specially trained to deal with fires (that's where they get that clever name). If things get out of hand they are happy to come and do their job.