Bassat wrote in post #18446462
I use slow zooms because I have fast primes. And they are cheaper, smaller, lighter. Mostly cheaper.
I agree. There's a lot to be said for a set of good primes instead of a top of the line zoom. 35mm f/2.0 IS, 50mm f/1.4 (... ... yes, I have heard all the criticism before already ... but I still think it's a more than ordinarily usable lens if you can get hold of a good copy) and 85mm f/1.8* would be a good set of modestly priced fast Canon primes that would make up a pretty complete portrait set, taken together with what the OP has already (arguably with some redundancy, since he already as a 100mm lens in there).
*Out of those, the 85mm f/1.2 would be the L range substitute I'd most want to have (and the second hand market for that lens should offer improving prices now that the 85mm f1.4 IS L is about to be released). It's not everybody's cup of tea but, when you get it right, the images have a unique quality that I find almost bewitching.
There are good non-Canon fast prime lens alternatives too, of course.
But this isn't answering the OP's actual question.