US Citizen in Europe and Returning to the States

[Debberino]

So we are from California but live in Ireland. My daughter is 13 1/2 months, 18 lbs and 27 1/2 inches. She currently has a Maxi Cosi Cabrio Fix which goes up to 20 lbs in Ireland and a Graco seat (that came with our travel system) in California.

We travel a lot and will have to buy her a plane seat this Christmas. We are also moving back to the States summer, 2010. I would like to buy only one car seat for her but need advice on one that is rear facing, that is authorized for airplane seats, and that is legal in the States.

I looked at the Britax's but they are too big for my tiny Nissan Micra in Ireland. My Micra has no latch system.

Any advice is appreciated....I am going to start looking next week as I think DD might have gained some weight (after getting over her recent illness).