I'm about to stick up some cheap fencing/hoarding (OSB), and it needs to be painted. I also have some slightly rusty gates, and several other bits and pieces that could do with a spruce up. I have a compressor, so am intending to spray the OSB panels, the gates I'll brush. I want to do as little prep as possible, especially with the gates. So ideally I'm after something I can just slap right on. No surprise here; I wish to pay as little as possible. I've got about 40-50ft of 7ft boards to do, both sides. Has anyone got any recommendations? Am I best with gloss, satin or matt? How much am I likely to get through (I'm wondering if 5ltr would suffice, would have to be thinned slightly to spray anyway)?