I have the Fugi Q4, would would never conceder anything less than a 4 stage. My next choice would be the Apollo but nothing smaller than their 1025.
For latex paint an HVLP system is not the best answer, with a pressure pot they are not to bad but still not the best way to go. If you do get a pressure pot get a 2 gallon minimum, that way you can just insert a 1 gallon can in it. You do not have to clean the pot as the paint stays in the original vessel.
I have all of the Fugi tips and you still need Floetrol to get it to layout properly.
I much prefer a pressurized gravity gun, easier to clean.
For latex an air assisted airless pump (very costly currently) or a conventional airless is your best bet. If you only need to spray latex once in a while you may want to conceder renting or buying a small airless.
The gun is the most important part of the system, the better the tips and gun the better the finish.
Here is a pretty extensive thread from JLC on the subject of sprayers;http://forums.jlconline.com/forums/showthread.php?t=48892&highlight=hvlp+spray+guns