okay so im confused on what i need in order to upgrade from my stock headlight and rear lights, i drive the 2000 a4 quattro 2.8, do i need to buy a conversion kit or can i just buy new headlights lets say if i wanted to go for HID lights..please help, also if anyone knows of any good places to buy from let me know

 

would halo headlights look right? do i need any type of conversion kit for these? and how strong should the headlights be, so they look nice and not too ricy