I'm editing a project that has 40% PAL footage and final output is NTSC. what would be the best way to do this in NLE? I heard the latest NLE can play and render it as NTSC, but the quality would not be as good. I have never done this before. I have both the latest FCP6 and Premiere. thanks!

Procoder does a better job at NTSC to PAL and vice versa than most encoders. I believe you can download a trial copy and try it out.