Halotron (a non-brominated HCFC mix) is not nearly as effective by weight as the brominated agents Halon 1211 and 1301. You need more agent (i.e., a bigger extinguisher) and the post-fire concentrations of halogen acids (HF and HCl) in the post-fire atmosphere will be much higher, possibly lethally so. Stick with Halon (pure 1301 if you can get it, 1301/1211 mix if you can't). And if you get a 1301/1211 mix, mind the "minimum room volume" limit on the bottle -- unlike 1301, 1211 is toxic, so you need to make sure your cabin is big enough that discharge will create a 1211 concentration lethal only to fires, not people.