I don't care for the HVLP sprayers. They tend to spray more air than paint and consequently need a bigger compressor. I use a siphon sprayer #97855 I get at harbor freight for about 20 bucks with a coupon. It will spray any wood finish but no cup gun is very good to spray latex paint. You have to thin it so much it doesn't cover very will and takes multiple coats to get the job done. Latex paint is better sprayed with an airless sprayer or a conventional sprayer with a pressure pot. The EPA is the ones pushing the HVLP sprayers because of automotive painting. A professional auto painter is required to use one or a amateur that paints more than two cars a year. There is no restrictions on most wood finishes. Oil based stains spray fine in a sprayer. I prefer to use them. It makes the job a lot easier to spray the stain on and then wipe it off. I don't normally use water based stains and the ones I use I just spray it on and leave it to dry.