If you are not sure yet what to use, keep the money in your pocket for a while and try out in the mean time a cheap Industar 22. Its a FSU lens, one of the sharpest. It looks exactly like an elmar but is in fact a copy of the more sharp Zeiss tessar. Because it is FSU it is really cheap and you can try out how it looks and performs. Then later you can decide if you really want the elmar (which performs a bit less than the Industar) and the Summitar which is a better performer then the elmar and industar.
I have all three so have some experience with these lenses.
Here is a picture of the lndustar 22 on my Z-2.
