Amryl Entertainment, for 20 years has offered complete runs of CAVEWOMAN series available through them. They first display their newest books, then you can scroll down and see the titles for the older series, and click on them. As small as the runs are on these titles, I'm surprised they still have complete runs. Because of a change in the format of their site, I initially thought they were no longer available. But they are.

http://www.amryl.com/index.php?pagename=cavewomanmain



Here at Lone Star, they at least list all the series and show the covers for each issue, whether or not they're in stock. If they become unavailaable from Amryl.

https://www.mycomicshop.com/search?q=cavewoman&pubid=&PubRng=



Again, I think the best of the bunch that I'd start with is the CAVEWOMAN: PANGAEAN SEA series:

http://www.amryl.com/index.php?pagename=ps1

https://www.mycomicshop.com/search?TID=251691