I need advice on a car seat for my 6 month old baby. He is exceptionally tall, not suprising having a mother of 6'2", and has out grown his baby carrier (mamas and papas primo viaggio)as the top of his head is now at least level with the top. He is however less than the recommended 9/10Kg for the next stage car seat and also only 6 months old. He is also able to sit unsupported for as long as he likes. Does anyone have any advice on the appropriate next stage car seat?