Oh where do I start? Actually, I'M that crazy car seat lady!
First and foremost, your 8 month old daughter needs to remain rear facing for a minimum of 2 years. This is what is now recommended by the AAP. Completely forget about the 1 year & 20 pounds. That's old, outdated, and could be potentially deadly advice. Children benefit greatly by rear facing for a minimum of 2 years, all the way up to 4 years old. Rear facing is 500% safer, and recudes the risk of serious injury or death in an accident by 70%. When you know better, you do better. Keep her rear facing.
That being said, I think I've owned just about ever car seat on the market today! Some I loved, some I hated. So I'll stick to what I loved and tell you about those.
Before I get started, let me tell you that a $50 seat is just as safe as a $300 seat. They all pass the same requirements and safety testing. The safest car seat for your child is one that's going to be used correctly 100% of the time, installs correctly in your car, and fits your child properly.
Do not feel obligated to buy a Britax. While they are good seats, they certainly are NOT the best. They were leading the car seat industry 5-10 years ago, but definitely not today. Many other manufacturers have caught up, and surpassed them. You can find car seats that offer the same features, or better features for less money. And Britax convertibles lack the leg room needed for older rear facing children. You want to get the most bang for your buck, right?
Also, please stay away from 3-in-1 type seats that rear face, forward face, and then turn to a booster. Those will NOT get you the most bang for your buck. They're fine for rear facing, ok for forward facing, and are HORRIBLE, TERRIBLE, NO GOOD boosters. No child should ever use one as a booster. It could be deadly. They do not fit a child properly, and are outgrown way before a child is big enough to be out of a booster seat.
Now, car seats that I do love :)
Evenflo Triumph Advance- around $120-150. Rear faces to 35 pounds (most kids 3-4 years old) and forward faces to 50 pounds (most kids 5-6 years old). When this seat is outgrown, the child will be ready for a booster. The harness on this seat is on an infinite sliding adjuster, so you never have to rethread it as your child grows. I absolutely love the knob adjusters to tighten and loosen the harness. This seat is very user friendly. Easy to install and easy to use. It's kinda the "Laz-E boy" of all car seats.
Graco My Ride 65- $150 Rear faces to 40 pounds (most kids to 4, though my 4.5 year old still fits) and forward faces to 65 pounds. This seat has 2 built in cup holders, which are a big hit with my 18 month old. Very easy to use and install, and lots of cut patterns (especially for girls!) Check out the Flair print at Target, so cute!
Learning Curve True Fit- $180-260 depending on model. Rear faces to 35 pounds and forward faces to 65 pounds. This seat is the tallest seat on the market. Every single child will make it to 35 pounds rear facing in this seat. For my child, that's 4.5 years old. The harness does not have to be rethreaded to adjust the height as your child grows. There is a removeable headrest for children under 22 pounds. Built in lock-offs for the seat belt.
Safety 1st Complete Air- $250 (on sale for $219 right now) Rear faces to 40 pounds (will get kids to 40 pounds, very tall shell!) and forward faces to 50 pounds. When this seat is outgrown forward facing, the child will be ready for a booster too. So the 50 pound forward facing limit isn't an issue. It's not necessary to harness to 65 pounds, unless your 4 year old is 65 pounds. The harness doesn't have to be rethreaded as your child grows, you simply move up the head rest. Awesome air cushions for side impact protection.
Sunshine Kids Radian (models 65, 80, XT, 65SL, 80SL, XTSL)- $165-270, depending on model. 65 and 65SL models rear face to 40 pounds and forward face to 65 pounds. 80 XT models rear face to 40 pounds and forward face to 80 pounds. 80SL and XTSL models rear face to 45 pounds and forward face to 80 pounds. XT models have headwings. SL models have Super-LATCH. These seats are awesome, and I love the 45 pound rear facing limits. But there are some compatibility issues, as they can be difficult to install and aren't always compatible with the vehicle.
Please check out your local car seat dealers (Babies R Us, etc.) and try your child out in the different seats. BRU allows you to take the seat out to your car to test it out for installation.
Good luck, and if you have any questions please let me know! Or you can visit www.car-seat.org and talk to a bunch of very friendly Certified Passenger Safety Technicians!
Also, please contact a local Certified Passenger Safety Technician to check your installed car seat to make sure it's in properly. 95% of car seats are not used or installed properly. Please make sure you're in that other 5%.