Both of these cameras will give comparable image quality, and for portrait photography, you are probably not going to use most of the extra features of the 7D, so if you are on a budget, I would get the 60D and use the money saved to put towards a better lens.
Both of these cameras have the same very high resolution crop sensor which, in my experience, demands top quality glass to get anywhere near good quality images out of them. When I got my 7D, I was disappointed with the image quality — until trying it with a Canon 24-70 f2.8L lens, which made a huge difference.
Be warned that both of these cameras are challenging to get the best quality images from because of the very high pixel density of the sensor, and I had to put in quite a bit of practice before getting the best out of my 7D. If you're not on a tight budget, then you should consider the 5D Mk II, which will give you better image quality and far better high ISO performance, which can be invaluable for taking portrait shots on location in low light.