you just need to replace the headlight motor. any dealership, as long as it's nissan, ha. you can go around to different tire places and ask what snow tires they offer, hell you can do a search online and find several brands and read reviews. blizzaks get good reviews. i personally prefer a studded tire in the "wet snow" states like virginia. in new york, i did great with a set of winter force or whatever they were, unstudded. for body kits, people like origin and a few others; my favorite is J.Blood - $2000 though
86k is awesome for an 89. the motor in my car had about 85k before i rebuilt it - none since, haha.
good luck and feel free to ask whatever questions you have. you may save time and frustration by using the site's search function with questions you think have already been answered.