[mr_sir]

are you sure you can't get your lightsaber yet? first time through i did dantooine as my first planet and i had my lightsaber before facing him. i got a piece from fighting visas, a piece on telos, and another piece from the salvager you rescue/kill in the ruins sublevel. then you just go back to bao-dur before going back to tell the mercenaries everything is ready. if you have an earlier save it may be worth doing this as it makes life so much easier. also, the trick i used was to go to the inventory screen to use medpacs as they heal instantly that way, rather than do it realtime. also, he only heals himself a few times so eventually he runs out of force points and then you can just lay into him and use medpacs to keep yourself healthy. also, equip and use the most powerful energy shield you have and keep renewing it the minute it runs out as this will protect from the energy damage from his lightsaber. also, the dexterity and stamina boosting stimulants would be useful as these will increase your vitality points and your defence level.

edit: what class are you playing, what weapon are you using, is it modified, and what armor are you wearing? modified armor with reduced energy damage from one of the overlays/underlays would be useful too.