Cisco ConfigMaker Replacement?

We are looking at creating a virtual environment for our company’s network. Something that we can change and “play” with without fear of taking down the company network. I?ve used Cisco?s ConfigMaker in college but when I tried to use it all of the possible equipment is outdated and Cisco is not going to be making any more updates to it. We run all Cisco equipment by the way. I?ve found Cisco Network Assistant but that seems as thought it is for real time management. We are not going to be applying anything directly from this software to the network equipment, its strictly for creating a virtual environment and testing within it. If you any of you have any ideas on where to look I?d greatly appreciate it. Thanks in advance.