Answering with a checklist;
- Are you certain port 80 is served by the Apache you expect - are your "404" responses showing in the access logs of that Apache instance
- are you certain your mod_jk module is being loaded (see Apache logs, or use one of the Apache status page views to verify); if the module was not loaded, the JK configuration section would be silently ignored
- are you certain your workers.properties is being found (Still, see Apache logs; you might also wish to raise the JkLogLevel in httpd.conf to trace for the time being; also, make sure you know where your JkLogFile is located)
Then about the SSL issue; mod_jk and mod_proxy_ajp should both work. If you just want basic "server-side SSL", and are not working with client certificates, then everything will be handled by your Apache httpd. If, on the other hand, you'll be doing client authentication using SSL client certificates, then I think there's another SO posting rather relevant to that use case.