Studio Portraits & fine art photos - including urban landscapes

I take portraits of people with tattoos so I need to be able to capture small tattoo details as well as full-body shots. I have been using a Nikon d80 but after starting an urban landscape project, I realized that the d80 lacks the depth I'm looking for. I've heard Leica is a good choice for portraits, but I also need something that can capture a fair amount of information and work well outside in changeable light and weather.