Placement depends on a few things, such as whether you want it to be seen easily or not, and the size. As well as personal preference.
If it's small, my recommended place for something like that would be the wrist or hip area.
Your question has made me realize that I haven't ventured into how tattoos show up differently due to different skin tones. I'll look into that :)
What i'd advise you to do is to get it outlined first, and see how you like it. You could always go back and get it coloured later, and I'm sure the tattoo artist will be able to give some recommendations :)