Welcome to the Bunnings Workshop community @jackdix. It's great to have you join us and many thanks for your question.
Were you looking for a spray gun for trade purposes or a D.I.Y. product? I've found the Dulux RapidFinish Paint Spray Gun provides a fantastic finish for a variety of household applications. I trust it would be suitable to spray your shutters. If you were looking for a premium product, I would suggest looking at the Titan Focus 500 XVLP Handheld Paint Sprayer which is the top of the line hand-held sprayer. With this unit, you'll be sure to achieve a superior finish on the interior doors, panels and intricate woodwork.
Please let me know if you need further help or had questions.
Let me also extend a very warm welcome to the Bunnings Workshop community @jackdix. I trust Mitch's suggestions were helpful to you. Please let us know if you need further advice for your painting project, we'd be more than happy to help.