I recommend against this. Tasks managers that are configured to auto kill apps can potentially lead to worse battery life. Android's resource manager would get confused by apps that are constantly killed by an app killer.
Here is a thread that explains why: http://androidforums.com/android-applications/335110-why-you-dont-need-task-killer.html
You can pose your question on the Android forums. There is a thread for your specific phone.
I manually kill running background apps. I never had problems with Task Manager from Google Play. Battery life for my phone increased significantly.