I was wondering if anybody had any hints on how to defeat Darth Malek on..

Well first of all, the Jedi that are being drained of their life are actually empowering him not you. One tactic is to use your life support packs to keep your health up while your attacking him, then when he runs off to drain life out of another Jedi you can either replenish your health or throw grenades at him. This final battle is hard and will require all of your skills.

Make sure you have the force power called death field, and when Malak goes to drain one of the Jedi, you go and use death field on one of the Jedi, this way you heal just like he does.

Or for the easiest way of all... Run from Darth Malak, and only stop when the Jedi come into your target. Instantly use your stun/disable/destroy droid force power and and destroy the source of which would probably be your demise...

Unless you have a crapload of life supports and like to do things the hard way. As soon as you can run after using that force power, do it (until the next Jedi). Occasionally, maybe, Malak will stop to throw his lightsaber or fall behind if he gets stuck on something... If this happens, use your throw lightsaber force power.

Not to mention, after you and him both deactivate your lightsabers (while your running from him), your pretty much free to use all the heal power you want. Just use it and keep running. When he's down to hardly any health, and you've destroyed all the Jedi, finish him!

If you do not have stun droid of a better version of it, you can also us force lightning on the jedi, and force storm is VERY useful when Malak force jumps, he is caught in mid-jump and falls.