Books could be written about the different products available and what spray system type is best. And even then, there would be many disagreeing with the conclusions.
Thepm4 is right about a stage two not being a choice for pretty much anything out there. Even stage 4 turbines will often struggle unless many products are thinned excessively - sometimes to the point of affecting the integrity of the product.
My short answer to your question, and again, others will have other thoughts about this, is as a beginner, a decent, used Graco 395 with a selection of tips would be a fairly good way for someone relatively new to the trade to start out with. I have one and used it to pretty much spray anything with nice results though it does take practice and experimentation to develop your techniques as well as what tips work best for what you are trying to spray. Wish I could be more specific and encouraging with my advice but as thepm4 and I have stated, this is a big subject with many variables. Perhaps others will weigh in.