Juniper in GNS3

Hi, i'm CCNP level in Cisco and I have just got a new job where almost the entire estate is Juniper so i NEED to get up on my Juniper skills and start labbing the way I've always done with Cisco products.

To best go about this from layer 2 switches to routers and firewalls what are my best bet for downloading what images to run in GNS3?

I've looked and come across the SRXv that is a firewall? But then I've read that it can do everything from access layer switches to acting as a firewall?

Are there any other great sites out there to such as networklessons.com (for Cisco) that apply to Juniper?, that site helped me alot with my CCNA & P...

Thanks again everyone!