The new 50 2.8 is a gem if you like sharp and small. The original design 50 2.8 made from 1958/72 is not far behind it. The biggest difference is at 2.8.
Many feel the Summicrons are close in price and size, and you get an extra stop, making the elmar a bad choice. I disagree, but then I have 3 summicrons and both models of the elmar 2.8 and the 3.5 elmar.
If you want to take pics in the dark, a Noctilux or new 50 1.4 should be first. Very few of my pics are 1.4, so my current favorite is the new 50 2.8.
I feel a 35 makes you too close for portraits and thus not for me. A 35/75 is a nice combo.
I would plan ahead the entire lens purchases, then start with what you wiill use first. That way you don`t end up with a 28 and 35 which are too close. 24/35 are more appropiate.