There are so many arguments about resource usage by antivirus software... the last thing I expected was a request to run it in rosetta 🙂
Lion can not run applications that require Rosetta. Your best bet is to upgrade to newer versions of the software.
If that's not feasible (either economically or for other reasons), then you'll need to keep another partition on your hard drive with Snow Leopard on it, that you can boot to when you need to use those older applications.