No, your baby is absolutely not ready for a booster seat. Its vital that a child is kept in a 5 point harness as long as possible and there are alot of great seats out now that allow you to do this. Many parents, including myself, keep our kids rear facing as long as possible also. Having a child FF increases the risk of neck/spinal cord injuries during a front end collision. Here is a picture of my 2y/o who is about 24lbs. 34" tall with a 13" torso riding RF in her Uptown:
The Uptown is $99 at Walmart (you usually have to order it) and it RF to 35lbs. but only FF to 40lbs. But I intend on buying the Graco Nautilus for her anyway so that is why I bought the Uptown.
If you want to go back to RF here are some great car seats that will allow you to do that:
Recaro Como/Signo (~$249-$290 depending on model) - top harness height is around 19 inches (Signo is 18 inches, Como is 19 inches) and harnesses up to 70 pounds (5-35lb rearfacing).
Sunshine Kids Radian (~$199-$278 depending on model) - top harness height of 18 inches. Can hold a child up to 65/80 pounds (depending on the model you buy) (5-33lb rearfacing). This seat folds so it can be carried easily (though it is still a heavy seat to carry, especially around the airports). These seats can use the tether rearfacing. This seat is also pretty narrow when compared to other seats so often a good choice when trying to fit multiple seats next to each other in the car.
Evenflo Triumph Advance (~$129) (don't confuse with the original triumph which is actually a very short harnessed seat)- top harness height of 17.5 inches. Can hold a child up to 50 pounds (5-35lb rearfacing).
Compass TrueFit (~$179) - top harness height is 17.25 inches. Can hold children up to 16 pounds (5-35lbs rearfacing). This seat has a removable headrest for babies 5-22lbs rearfacing which might make this seat easier to fit into smaller cars rearfacing. The headrest is required forward facing and when rearfacing above 22lbs.
Britax Marathon, Boulevard, Decathlon (~$229-$289 depending on model) - top harness height is 17 inches. Can hold children up to 65 pounds (5-33 pounds rearfacing, though seats manufactured in 2008 should go to 35lb rearfacing). These seats can tether rearfacing.
Fisher Price Safe Voyage (~$149) - based on the Britax Marathon shell)- top harness height is 17 inches. Can hold children up to 55 pounds (5-33lb rearfacing). This seat is being discontinued so it is hard to find and might have older manufacturing dates (seat expires 6 years from when it was made).
Depending on what kind of car you have, height & weight of your child and your budget we can give you lots of more great advice!! :thumbsup: