alpha omega car seats toddler

Can I upgrade Car Seats?! please help!?

My baby is just a few days over 3 months old and already nearly 18 lbs (I KNOW, he is huge)!
I switched from an infant car seat to an Alpha Omega convertable, and I HATE IT! and my baby hates it!
I want to change my whole system to Orbit!
and I’ve heard wonderful things, but is it too early for him to be in this toddler car seat? It says from 15 lbs, I’m just worried because usually babies are much older at 15 lbs. He has pretty good head control, but I need advice.
here it is:
http://www.orbitbaby.com/products/tcs.html
this car seat can be REAR and forward facing. I am not turning him around until one year and 20 lbs.

i have the Britax Boulevard. It holds from 5lbs – 65 lbs. I LOVE IT…. and very safe, same price range, maybe a bit cheaper. check Ebay—-they are cheapest there from overstock companies

ALPHA OMEGA ELITE CONVERTIBLE INFANT TO TODDLER CAR SEAT $69.00

Safety 1st Alpha Omega Elite 3 In 1 Car Seat $199.99 For children 5-100 pounds and 19-52 inches in height. 1. Infant: 5-35 lb. 2. Toddler: 22-50 lb. 3. Youth: 40-100 lb. It’s a booster too! Use up to 100 lb. Meets or exceeds federal safety standards. Side impact protection. 1. QuickFit harness system adjust harness height in one easy step! 2. Removable infant head support. 3. 4-position recline adjust with one hand. 4. Up-front harness adjustment. 5…

death of young children in child seats puts spotlight OTTAWA – Bartolomé Pierrelus and serious Laure Rose already in such pain. Then March 3, the day before you touch your child's small coffin – two years old, Shawn Stewart Marc died in a crash Feb. 17 at the Queensway, the stepfather at the wheel – a police officer visited their door.