Air compressor

a tiny compressor is never going to power a HVLP gun, compressors work of CFM, you need to make sure that there is a higher CFM number on the compressor than the gun. For small panels you could get away with something like a 10 gallon 2hp compressor with a CFM of around 6, and then a conventional gravity or suction feed gun for shooting paint.

Paint guns, if you have the budget, get seperate guns, if you are on a tight budget, at least get a different gun for primers and sealers to colours and clears. Personally i use 4 guns, one for primer, one for colour, one for clear and one for sealer. Primer gun is conventional, colour and clear guns are HVLP. My compressor is 40gallon 3.5 HP with a CFM rating of 15.  Always spend the maximum amount you can afford to. This will pay off with your finishes.

So Check Ebay and see if you can find a compressor and two paint guns in your budget, post them on here, and we can see if they will work with each other!