I would purchase a Snap 4. We really like ours and works better than expected on rougher terrain so I'd bypass the air tires for now. I don't have a carseat attachment, but our Graco actually fits very tightly in the seat without it. A bungee cord could be used to make it safer. I find the sunshade very efficient. I think you will find other times a lighter stroller such as this comes in very handy.