Re: Which convertible to get for a newborn thru...
There really isn't one that will do it all. There are some that will get you to booster age. Boosters are relatively cheap, though. I would suggest the Graco My Size/Size 4 Me or Graco My Ride. Also, the Radian does make a decent seat for an infant, but at a 45 degree angle, it will take up TONS of space. The Maxi Cosi Pria is also really nice and has an insert that will allow a newborn to sit at the right angle, but have the actual seat a bit more upright.
In short, these are the options, IMO:
Graco My Ride
Graco My Size 70/Size 4 Me/Headwise
Diono Radian R120 or RXT(technically, they turn into boosters, but are not a great booster)
Maxi Cosi Pria
Jacky, CPST and wife to Tim
Mama to my little red heads, Kenzie