I know not every body here is into air ride suspension, but for the few that are this place is a goldmine! Also, if you're looking for misc air fittings, these guys have had what I needed almost every time!
Western Air Brake
1063 Thomas Ave
I've been there a handful of times and every time they've had the air ride fitting or air line that I needed in stock and priced extremely well. Not even worth looking online because their pricing is so good!
I just picked up four fittings today for a friends car, they cost me $0.70 each. Online they are $3.49 USD each + shipping.
NOTE: They are an air brake shop, not an air ride shop. Many of the fittings/lines are the same but don't expect these guys to know or tell you what you need for your air ride setup. Go in there with a proper descriptive list of fittings and sizes that you need and they will get you want you need.
Example of a good list:
4x 3/8 NPT to 3/8 Push to connect
Example of a bad list:
4x air tank fittings