Don't waste your money on an Alpha Omega. For the cost, you can find a seat that will rear face your child longer, harness your child forward facing longer, and is overall a better seat. Plus they make awful booster seats and have failed (like killed the dummy failed) every crash test they've ever been in. So you can't use it as a booster either.
Evenflo Triumph ADVANCE wil lrear face to 35lbs, forward to 50lbs, and will fit most kids rear to 3, forward to 5/6, and is $130.
Graco MyRide 65 will rear face to 40lbs, forward to 65lbs. Fits most kids to 4 rear facing, forward to 6. AWESOME seat, padded and good side impact protection, and its $150.
First Years TrueFit will rear face to 35lbs, forward to 65lbs. Fist most kids rear to 3, forward to 6/7. $150-$200
Sunshine Kids radian will rear face to 40-45lbs, forward 65-80lbs. Fits most kids to 5 rear, forward to age 7+. $200-$300
Britax Marathon or Boulevard will rear face to 40lbs, forward to 70 (new models, older were 35/65). Fits most kids to 4 rear, forward to age 6/7. $250-$300.
Any of these seats are a better option than the Alpha Omega. They will last longer for your child both rear facing and forward facing as you want your child rear facing as long as possible (AAP recommends 2 and 30lbs) and forward facing in a harness as long as possible (at least 4 AND 40lbs, but its best to kee pa child harnessed until 5/6). Google EXTENDED REAR FACING and JOELS JOURNEY for more information.