Those are pretty sweet. I didn't even know Marin was still in business!
1 and 2 are pretty good value, and the price jump to 3 for a belt drive I'd say is worth it. More than double price jump from there to the 4 DLX I don't think is worth it for rack, fenders, kickstand, generator hub, and lights.
It's a nice touch that the rear rack and fender appear to be a single item (I've always thought that's an obvious design plus that should be common), but the front fender is laughably short -- it needs to get down near the ground to protect your shoes at the bottom of the pedal stroke.
So of that range, if you like the belt drive, I'd recommend buying the 3, and adding as many of those extra features you want. I bet if you shop carefully you could do it all for another $300.
If the belt drive doesn't catch your fancy, the only difference I'm seeing between the specs of the 1 and 2 are 3-speed --> 7-speed, and alu fork --> steel fork. And the paint on the 1 looks way cooler. You already have fairly wide tires, going to a steel fork is not going to make that much difference in comfort. So if you are in a flat area and can get away with a 3-speed, I'd get the 1. The extra cash can go towards the fenders etc that you want.