Maybe this will help - I've used just about every airbrush on the market including the overpriced ones. An airbrush is usually only as good as the person using it, except the cheapass Testors, or Badger brands which are overpriced, and over rated. These work as long as you warm your can in warm water to make the Co2 last longer. If your getting splatter from the tip, this is because you have insufficient cleaning capacity of these poorly designed nozzles. Paint gets clogged as it builds. This makes for poor performance. Soak the tip in acetone, or paint thinner. You may need a stronger solvent like acetone, or lacquer thinner if it is indeed dried paint, as it is more difficult to remove the longer it sits.
You also might need to thin your paint if it doesn't spay to well. I've found that the cheaper the airbrush - the cheaper the quality of performance. Iwata is over rated too, as most of its' users think the more expensive, the better. Nothing could be further from the truth! This is a case of "I bought one because XXXX bought one". It's only as good as the person using it. I've heard some who've had success with it, and others who aren't impressed with it. I wouldn't recommend it over anything you can get for $60 - $100 anywhere. Paache is easy to use, and clean, and get true professional quality - plus you can get parts for it cheaply, not expensively, and the revenue stays in our country unlike the Japanese made models.
You can get an airbrush just about anywhere, but I get mine from www.bearair.com They have excellent prices, products, and service. I bought the Paasche VL after trying everything else on the market. I got my compressor from Harbour Freight for $60.00, but they no longer make, or sell it. You may be able to get one from just about any home improvement store, hardware store, or other similar retailer.
~ Cobra Chris