What mount is the Zeiss 55mm? I don't have the Sony, but have been hanging onto my C/Y Zeiss lenses partly with the idea they should be very nice on the A7. The 35/2.8 Distagon is a particularly nice lens.
The problem with Maxxum lenses is that they mostly produced zooms for that system. They were good for the time, but hard to get excited about today. There are some good prime lenses, but the great ones are somewhat uncommon and so not cheap. They will have the advantage of excif data, and autofocus if you are interested in that. The 24/2.8 seems very good to me on APS-C and will have the advantage of longer back focus compared to Leica lenses.