That’s a lot of plugins but I’m going to advise you to install one more. Install WordPress Plugin Performance Profiler (P3) | Go Daddy Blog | Go Daddy Support on your site and run it, it will tell you which plugins are using up your resources. Once you’re done checking and removing those that slow you down, you can disable it. I leave it on the site and run it every now and then just to check things.
Part of your problem can be not enough ram. If you have say 512mb of ram and are running cpanel plus all those plugins, you will be slow. But before you go spending $ on upgrades run the plugin I posted and see what you can remove or replace.
Hope this helps.