OK:
#1, they're chemically the same thing. Antimony's valence means that its "sulfide" is two antimony atoms and 3 sulfur atoms (trisulfide).
#2, if you are asking such an elementary question on a board like this (as opposed to one of the boards such as fireworking.com where you will find the serious pyro manufacturing community), and being a little churlish when nobody answers, you should not be messing around with this! It's quite toxic on its own, and requires protective gear - respirator, gloves, protective clothing. For pyrotechnic use, it's specifically not to be mixed with chlorates or the mixture may self-ignite. Even with perchlorates, the mixture is extremely sensitive.
#3, if you are going to pursue this anyway, don't do it where anyone else is exposed to your chems or any fire or explosions that may result (definitely not a basement or garage activity); make sure your will is drawn up; and check that your life insurance is paid up and has the correct beneficiaries. I'm completely serious about this, it's the best advice I can give you.