Need a new carseat!

For a tall baby. He is 6 months , 19 pounds and 28 inches. He is 2 inches away from outgrowing his current carseat. He has been at least in the 95 percentile in height since birth. I really need/want him to rear face for 2 years and I've been looking for a car seat but there are so many and not all of them specify the height. Any suggestions for a seat that will accomidate a tall boy for as long as possible?