Car Seat Help

Okay so I've been looking at carseats and researching and so far I like Graco the best. Well I'm having trouble deciding what i need to get. I wanted a convertible carseat to save money but the convertible seats arent compatible with the strollers for infants so I'd need to buy an infant stroller and then a bigger stroller later on and I need my carseat to be compatible so that I am able to push my infant around. They have great stroller travel systems but they are only for children from infant up to 35lbs so I'll need to buy another carseat later on (I'm guessing at 2 or 3 years old). So what would you ladies do? Would you buy a stroller and convertible carseat separately and buy a bigger stroller later on or would you buy a stroller travel system that comes with an infant carseat then buy another larger carseat later on? Is there another option? I'm so confused. Please help.