An orbital sander is a hand-held tool. It works by rotating itself elliptically to create a smooth surface. This makes it great for making or refurbishing wood furniture. It could also be used to remove rust or paint. For a smooth surface in a short time, an orbital sander could work for you.
Some are gravity feed, and others are suction feed.
With different nozzle sizes from 1.3mm up to 2.2mm, you will be able to find a spray gun that is best suited for what you need to spray.