When you get to the "Select Packages" screen, click on the "View" button until it says "full".



Then scroll down the list until "gzip" is visible in the "Package" column, and click on the swirly arrow thing in the "New" column once. The version number of gzip should appear. Do the same for "ncftp".

Then click "Next" until it's done.

(Note that mine says "Keep" where the version number would appear, because I've already got gzip installed).