what other parts that need to be replaced when replacing the front struts?

The upper bearings / strut mounts need to be replaced if the rubber is cracked or dry rotted, or if the bearings are noisy. Being proactive, it's not a bad idea, since either you replace them outright, or you swap them from your old struts to your new ones when you swap the springs over. Examine them closely and ensure they are OK, or just change them.

Why do all that additional work? .. The absolute best route to take here is Complete Struts or Quick Struts! .. Use Google search.