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Pressure washers don't use compressed air they use a high pressure pump. They aren't difficult to use and if you by a new one the instructions that come with it are all you need. Lowes has Troybilt washer that are first rate and reasonably priced.
The airless paint sprayers on the other hand aren't very good and probably won't do the job you want. Since you'll only be painting your house every 8 to 10 years using a brush is probably your best bet.