If you need it to be more affordable, I'd def go with the Graco, I have one for my 2 year old and it is great....it can rearface to 40 lbs (only seat on the market that does), the First Years True Fit or the Evenflo Symphony. They are bigger seats cause they accommodate kids up to 65 lbs so make sure you have room in your car.
If you can spend the extra money, Britax are great....they have a longer expire date and better features. Safety wise they are really about equal, the Britax just has more convenience features and is a little easier to use. I have a Marathon in my main car for my 2 year old.
I would not buy a combination seat of any other brand. They CLAIM to work up to 65 lbs, but the truth is they will outgrow the seat by height before they get to that weight. And the other combination seats don't make very good boosters when you get to that stage (don't position the belt right).
When you get the new seat make sure to read the manual and install correctly, there should be no more than one inch of movement at the base. Also the seats that are "all in one" usually have a foot or an adjustment you have to do to make it work rearfacing. Just be careful and do your homework.
If you have any questions, feel free to send me a message, I am a CPS tech and would be happy to help you. Thanks!