Our main site domains has already a SSL certificate. However, we need ssl for our another environment for accurate testing. Is it possible to use another ssl from a different (cheaper) provider for our domians? We have a load balancer with different ip's so having unique IP's should not be an issue.
It is most certainly possible. I've worked with a few companies who buy expensive certificates (eg. Extended Validation certificates) for production sites, and cheaper certificates (Domain Validated certificates), sometimes from different Certificate Authorities, for development and testing purposes. That being said, you might want to approach this a little differently though, especially when considering an "accurate testing" motive First of all, SSL certificates primarily provide 3 things: 1. Encryption 2. Integrity 3. Authenticity I would recommend you to go with comodo SSL Certificate. They are the cheapest SSL Certificate available at present.