Yeah, 135mm is too long for indoors and portraits on anything but a full frame camera. Essentially it becomes a 200mm lens with the crop factor and that is too much for everyday situations. Back when I took tight headshots a 200mm lens is what I used on a full frame camera. Unless you have a need for this niche lens, I would forgo this purchase.
You don't have anything wide angle I noticed. I would go for the 17-55 f2.8 IS or the 17-40 f4 L. Some people don't think this lens is quite wide or long enough. If you need wider and a bit longer to bridge the gap to your 70-200, you could look at the combination of the 10-22 and either the 24-105 f4 L IS or the 24-70 f2.8 L. I have the 10-22 and it is a great lens with L quality glass. It's good for landscape images and specialty wide angle stuff.
I have thought about paring down my lens collection and going with the 17-55 f2.8 IS and the 70-200 f2.8 L IS. Two lenses is easier to carry than 3 or 4 is my thinking and I think I could live without the super wide angle. I have held off on selling the 10-22 though as the glass is so good. Truth be told I'll probably end up keeping the lens as I can't get myself to get rid of it.
I've focused a lot on zooms here. If you are a prime type of guy many people like the 24mm, 35mm, and 85mm L series lenses. It's more to carry and pay for but the quality is top notch.
Obviously, keep the sigma 50/1.4 as it will be your indoor low light lens.