If you're using RedHat, I'd recommend mod_ssl, only because the RPM setup is fairly easy and quick and the modular support of mod_ssl in Apache is easy to setup, all you need to do is edit your httpd.conf and restart httpd to load it up. If you're using other distros then it depends. The RedHat Knowledgebase FAQ has some information on setup (with lots of typos and mistakes, but informative nonetheless). The FAQ also mentions Verisign and Thawte.
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If you're using RedHat, I'd recommend mod_ssl, only because the RPM setup is fairly easy and quick and the modular support of mod_ssl in Apache is easy to setup, all you need to do is edit your httpd.conf and restart httpd to load it up. If you're using other distros then it depends. The RedHat Knowledgebase FAQ has some information on setup (with lots of typos and mistakes, but informative nonetheless). The FAQ also mentions Verisign and Thawte.