Assuming you mean a long handled gas burner for burning weeds, I have no idea where to get one in Chania. Possibly Schetakis
. There are two Foteinakis shops within about 50 m of each other. Probably best to try the big yellow one first. If they don't have one then they might know where you can get one.
You can get them online in Greece, for example this one
and others at the bottom of the page.
If you mean a weapon for shooting a stream of flaming gasoline, oil, napalm, etc. then you probably need a military supplier?