Don't go for second hand ones, as you don't know if they have been in a crash.
I have a britax one for the older one, it is forward facing, and wouldn't take a newborn.
The one i bought for the newborn was this....
http://www.toysrus.co.uk/Product.aspx/bruh...velgraco/709778
It has a 'docking station' so it is realy easy to take the seat in and out. It also connected to the pushchair.
Then when she was 9 months old, i bought one of these.....
http://www.toysrus.co.uk/Product.aspx/BruH...elBritax/715654
She is now 3 years and still fitting in it no problem.
Remember, you cannot cut corners when it comes to saftey for the little un.
Good luck in the hunt.
Make sure you try out the seat to make sure it fits your car before purchasing.