I faced the same issue as you. For me, it was simple - keep shooting my 60D for another four years, buy the 5DII now, or wait for the 5DIV because the 5DIII price seemed ridiculous. I decided to buy the 5DII and I am surprised by how much I love it. It is an excellent upgrade from your current camera, especially with types of shooting that you do.
With the 5DII, you can get usable shots through ISO 3200, and grainy/less resolved shots at ISO 6400. This is the most liberating aspect of the 5DII. This will make your low light shots (gigs/dj/street) significantly easier than with your crop camera. Also, the AF seems to work well in low light. The one drawback for street shots is the size -- it's not a small, discrete camera like a rangefinder or Nex.
The light roll off of the 5DII is magical. I think this aspect of the camera, along with the noticeable depth of field, should result in beautiful portraits.
Given your options, the 5DII makes good sense, especially if you get a good deal on one. For the type of shooting you do, it will be a significant upgrade. It will also be an upgrade in other ways (e.g., build quality, fast processor, etc.).