If you doubt between the canon 50 mm 1.4 or 1.8, choose the 1.8.
The price difference isn't worth it. I own the 1.4, and have owned the 1.8. At 1.4 the sharpness is not that good, and I find the quality very similar at the other apertures. 1.8 is a bit louder, when using autofocus. Sharpness of the 1.8 is very good for that price, especially at F/8; at which you will shooting when your aim is portraits or landscapes.
My experience with canon 28-135 IS; I just got rid of it, very disappointed with it.