B.H.
I have the Graco Safeseat carseat and stroller travel system. They are pretty girl colors and match both the stroller and carseat. Living in MN and having the freezing cold I like the carseat that it goes up to 30lbs because longer I can leave my little baby in that seat. It's so much easier to use a infant seat and get the baby ready inside the house rather than take her in and out of a seat in a car.
The point of the travel system is that the carseat snaps into the stroller. So when my baby is fully asleep as most newborns are I can take her stroller out of the trunk and snap her carseat into the stroller and away we go, never waking or transfering my happily sleeping child. When my child is older like a toddler I can just use the stroller. Most newborns don't fit to well in strollers anyways the straps are huge etc.
You can do whatever you want and just buy a carseat or just buy a stroller they dont even have to match. Graco does have a variety in carseats and strollers some are cheaper and crappier than others. Our stroller is the Quatro it's heavier duty, has more features. I like it but it's HUGE and plan to buy a more compact stroller when we hit the toddler days.
Graco also has different variety's of infant seats some are more exspensive than others and have nicer features like front strap adjustment vs. rear strap adjustments, more padding etc.
I bought mine at Babies R Us and got a babies r us exclusive pattern which means noone else sells it, I like that because I like to be somewhat unique and not match the rest of the world. I did go for the "girl" pattern because when I had my first daughter that wasn't a option back then and I love my pinks and purples. I also buy a new carseat for every new baby as they do expire after about 5 years and get beat up with everyday use and baby spit up etc.