Maclaren Twin Techno - light, easy to use, full individual recline for each seat. Very smooth.
We've used for 2 toddlers (DS and DNiece). DSister also uses for her 2 kids, from the time the 2nd was about 3 weeks old. She just finished a DL trip and it worked great for her 2 (her son was 10 mo and daughter is almost 4).
It won't hold a car seat, but I belive in minimizing the amount of time an infant is in the car seat bucket - either put them in the stroller with full recline, or carry them in the infant carrier (baby bjorn / ergo)