Will I still get that deep dark color as I would on a single stage? By the way what black has a darker tone/or darker color
Yes. You will get a deep color. Just make sure that base coat is flat as can be. Minimize the sanding scratches in the base coat. If you are getting sand scratches that look pretty bad, buzz over the car with 1500, or 2000 depending how bad they look, then lay down 2 or 3 more coats of paint. Then lay 3 coats of clearcoat down.
It won't hurt to lay a few more coats down, because you just took off some during the wet sanding.
Just tell the paint supplier you want Dupont 99 black. It is just a plain black. When I do an entire car, I usually order 1 quart or paint and 1 quarter of clear, just to cut in the jambs..(fenders, doors, rockers, trunk, hood area.) Then I order 1 gallon of Dupont paint. 1 Gallon of Dupont Base Maker...which is mixed 1:1. I order 1 gallon of Nason clear, and 1 quart of Nason activator. I usually have some left over depending how the painting goes and how much clear I use. It's better to have more than to run out before your satisfied with the paint/clear on the car.