Is there really a necessity to purchase/register for a complete travel system stroller like this one:
http://www.toysrus.com/product/index.jsp?productId=3980773&fromRegistryNumber=47713329&product_skn=174804

or can we just live with registering for a car seat thats compatible with this:
http://www.toysrus.com/product/index.jsp?productId=11820851&fromRegistryNumber=47713329&product_skn=530412#showReviews

& just using that? What is the difference?!