Simply create a new utc file: rename the utc file, give a unique name like super_sith.utc then opne the file with gff editor and go to the tag field. Change it to super_sith. Do the same thing with the Template ResRef field. (you can replace super_sith by whatever you want this name won't appear in the game). Change your recruit script accordingly:
 void main()
 {
 RemoveAvailableNPC(7);
 AddAvailableNPCByTemplate(7, "super_sith");
 }  
 the number 7 will replace T3m4, for other npcs, use: 
 BASTILA = 0
 CANDEROUS= 1
 CARTH = 2
 HK_47 = 3
 JOLEE= 4
 JUHANI= 5
 MISSION= 6
 T3_M4 = 7
 ZAALBAR = 8 
 BTW, you should use a unique .utc file each time you do a recruit mod. Otherwise, when you drop the .utc file in your override folder, you will replace every .utc file in the game that has the same name . Remember that when you do a recruit mod, you have to change the faction and the scripts that determine the behavior of your npc to make him a party member (check this thread: 
http://www.lucasforums.com/showthread.php?s=&threadid=129961)
 If you don't create a new .utc file with a unique name... Just imagine what will happen when you run the game: you will have a ton of new friends, especially if you use a sith soldier .utc file :D