Do you want to mod it in a map.ini so it affects a single map, or in a full mod so you have to install a mod to see it?
I have a Generals mod where the biohazard tech is armed with a flame thrower (he keeps his cleanup power too). He can be built by the GLA barracks. see:
Souped Up Generals Mod v1.04 - Planet CnC
Souped Up Generals Mod, Command and Conquer 3 Downloads, Command and Conquer 3 Mods