Symantec Access Management

If not, what advice would you give?

If so, anything I should be aware of/ plan for beforehand?

   If there are multiple plugin options, which one is best? 

I want to be sure we understand capabilities before scoping this piece of a project for our client, but in the Wordpress plugin marketplace, none of the SSO plugins specifically state that they work with CA SSO, so it's difficult to investigate further requirements. Hoping someone here has insight! Thanks in advance. 

Rachel,  This is not supported (i.e. QA certified), also there's no known CA experience with this WordPress CA SSO plugin.  But somebody else may comment if there's any. Internet search, and  see that someone has used or implemented a plugin for WordPress that appears to do something similar using the HTTP_USER_ID header.
https://github.com/navjeetc/siteminder-authentication

Rgds. Vijay