Redbull,
If your using 1/2" splittail rope, the tautline or blakes work just fine. If your interested in using french prusik, distel, swabish, youll need to drop your rope dia. to bout 5/16". Most guys are using Ultra-Tech but there are other ropes similar to this.
You can pick up the fp from the Tree Climbers Companion. If you have a sherrill catalog, they have pics of the distel & swabish.
When learning these, start low and tie it many times before going too high. I think no matter what you end up using, youll like the results much better than the Tautline.
Best of luck!