I recently purchased a Kobalt Gravity-Feed Spray Gun #0301329, Model SGY-AIR88NB that came with a 1.4 fluid needle. I'm looking for a 1.8 needle along with matching fluid nozzle and maybe an air cap. Is there anywhere where I can purchase items?

Since Kobalt has their products made by other factories, you would need to find the original factory that made this for them. I would start with calling Kobalt www.kobalttools.com/