Any gravity feed gun with a 1.3 or 1.4mm tip works well. There are major differences between them of course. Depending on what you are willing to spend.
Be careful with guns like the ones from Harbor freight, they generally have plastic pieces in them which can and will wear out very quickly, especially with solvent based paints.
The one I was using for almost everything is a great gun, by a company called APC, the gun is called the Artisan. I'm not a big fan of HVLP, specifically for clear. The APC gun is available for around $120US, but I'm not sure where you can get them online, I know they are available here, and I'm more than happy to pick them up and ship them out if you were interested.
I just recently purchased the mother of all spray guns, if you want the best then there is no better company than Sata. I have 2 of their guns, the minijet 3 HVLP and the Satajet RP digital. Even their lower end guns are fantastic. The RP digital is halfway between HVLP and high pressure. It uses about 50% of the paint that my regular gun does, but it atomizes the paint far far better than any gun I've used and it lays out glass smooth. I was hesitant to buy it because up here they are nearly $1000 Canadian but they let me take it and try it, after 5 minutes I had decided to buy it. However, it's what I make my living with, if I was just painting for myself, the APC Artisan would be my choice, Devilbiss makes good stuff too at a good price, Iwata has some fantastic guns as well, the LPH400 would be my choice after the RP digital.


What I learned after spraying with the RP digital compared to the guns I thought were awesome before, is that my old guns were like driving a trans-am, the RP is the Ferrari, both work, and both perform well, but there are definitely differences.
After using it, if you are willing to spend the money, I wouldn't recommend anything but the Sata line (no, I dont' work for, have any affiliation with, or get good deals from Sata, I'm just being dead serious)