A full windshield and no rear window is the worst case scenario for dust. As you drive you are creating a low pressure zone behind the windshield, which then sucks in air from the sides and rear. If that air contains dust...
Adding a rear windshield will help because then you only suck it in from the sides, but then you will get a ton more dust on your cargo area, which is where your air intake is, so will dirty your air filter faster and get more dust in your clutches.
A vented front will help a little for cab dust, but nowhere near a half front.
A half front and mesh rearis the best compromise, as it allows air to flow through so you get WAY less can dust, and don't have the cargo area issue. The rear screen protects you from mud and rocks flipped up by your rear tires.