DR (L), BSF, HK as your core and then the last two spots up in the air.
Sith Emp Trooper and Sith Marauder probably. That way you maintain full Sith Empire. Alternately, if you can get GMY really fast sub him for one to spread Ten Up before enemy BSF gets CBM off.
SET has the invaluable pretaunt; without him you'd want zGBA or zKRU for a pretaunt but SET is ideal since he autotaunts without having to take a turn. SiM's value comes from the sheer volume of debuffs on DR teams, especially in DR mirrors. Modded and geared properly he should even be able to liquefy Malak, which is going to be the biggest discrepancy you have to face. Of course, you can always include Thrawn because Fracturing Malak can also give you the edge you need.
I think those four would probably be your most viable options without Malak. I know there was a guy on my shard who ran DR, BSF, HK, and then Talzin and Zombie for pretaunt and Plague. Maybe not the best lineup but something you could play around with if you wanted.
