I wear NC45 too. I went in to Sephora and got matched for M62. Tried it on as soon as I got home and I LOVE IT! I know this post is old but someone with similar skin tone to ours is bound to run into this post.
Oh TeeTime I tried a sample of this foundation today and am in LOVE with it. One application was all it took - amazing coverage....no breakouts and did not look cakey.
Feels light weight too. I don't know an answer to your shade question. I am an NW20 in Mac and the shade Light 48 worked well on me today, if that is any comparison for you. Sephora.com shows this shade as being "Medium" but I am definitely a light skin tone, so my first inclination is that this runs light? I don't know what others are experiencing with the shades.
You can go to Temptalia's foundation matrix and enter your Mac shade and it should pull up what you would be in Kat Von D.
Have you tried this foundation before? I had an awful experience with it, TeeTime7. It was so heavy and cakey. I looked like I was wearing a mask. I tried applying it multiple ways too (brushes, fingers, damp beauty blender) and nothing looked good. It also made me break out and I only wore it a few times.
If you are looking for a medium to full coverage foundation that is great for oily skin, I would highly recommend the Hourglass Immaculate Foundation.