I'm not surprised its slow with the amount of stuff your running. If I were you I would stick to a decent AV (Avast and AVG are free and decent) and Spybot S&D, enable windows firewall - and if you have a router enable the firewall on that.
You dont need anything else if you have common sense.
I totally agree. AVG, Spybot, Windows Firewall and Router Firewall is enough but common sense is by far the best tool you can use when protecting your PC.