Double stroller suggestions

M
Any double stroller suggestions? I am due with my second in sept and my first is on 16 months and will be 18 when she is born. I'm looking for something not to heavy but something that can convert and easy to fold down. I have a Greco car seat so I was also looking for something j can snap that into. 
Please tell me your suggestions and why! Thank in advance girls!!! 
Xoxox
Xoxo