travel system VS. just car seat

Ok ladies, so this is my first pregnancy and I'm getting ready to have my shower so I've been going over and over my registry tweaking it here and there....I have the Graco Comfy Cruiser click connect travel system on my registry....but was talking to my fiancé, who has a daughter that's 14, and he was saying that he thinks buying a car seat alone may make it safer then buying a travel system where the car seat is made to click together with the stroller...but as far as I'm aware buying the travel system just means you're getting everything together instead of buying it all separately....so what I want to know is if he's right or not? Would I be safer getting a car seat sepearate from this or will this be just as safe??