Car Seats

So we are already getting close to max height on Lukas' infant car seat. Last doctor appt he was 27" long and 15 lbs 12 ozs. He is in the 85% for height, surprise surprise! (That means 15% of boys his age are longer then he is and 85% of boys his age are shorter) The max for this car seat is 29". So now we have to decide what car seat we want to get next. The options seem to be endless, and no website has a simple answer. Any tips from fellow parents?
Anyway doesn't he look cute in his searsucker suit?