Well i'll tell you this... If you want to get very good lights.. then you might want to go wit PIAA - there are other brands but i like them the best. HELLA i think is another brand... I know with PIAAS you will want to use THEIR wiring harness. I do not know if HELLA has one.
if it were me I would use th PIAA harness and just tie the factory harness out of the way..I would not use the factory harness with ANY LAMPS EXCEPT for a factory ONES.