Would 7zip make the archive any smaller ? It can sometimes make a big difference and give a smaller download size for the end-user. Zip files usually have the worst compression. Use 7zip or Peazip with 7zip settings on ultra compression. You can get even smaller compression if you add your own compression commands before starting.
This is a quote from a friend who compresses archives using 7zip with very good size results:
"The parameters I generally use are -mx -myx -ms=15g -mqs=on -mmt=8 -md=1024m -mfb=273 which in GUI terms is LZMA2 Ultra preset with 1024 MB dictionary size, 273 word size, 15 GB solid block size, and 8 threads.
The qs (sorting by type) and yx (analysis of all files) parameters aren't available in the GUI but can be added manually.
For this game I used 512MB dictionary since I was doing other things in parallel, and the difference would be only around 100MB at most.
I adjust it depending on how long I want it to run, since I usually do it in the background while working."
You don't need to go that far ,probably a basic 7zip archive on ultra settings would be much smaller.