You can work with any kind of unsupported device.
You just need to get sample event messages with you can feed your lab COLLECTOR.
Then extract that events from the database using LSDATA command to use with RSA enVision Event Source Integrator to create the package for installation of new device.
Hope this help you.
You can try solarwinds devices which is coming for free trial version , good for testing
Just make sure that you need to take the log files using the LSDATA utitlity which ensures that logs are in syslog format
When I say you, that you can work with any kind of unsupported device, I include the develop a new device from the scratch.
You don't need to purchase anything, just create a simple text file with rows of data, you specify the separator and fields, you can design your own Message ID.
The quantity of message ID depends of you, the structure of the file depends of you.
When you work with files you must create a File Reader Device in RSA enVision to process the file for your brand new device created.
To test, just copy your file to E:\nic\VERSION\Name_of_your_machine\ftp_files folder and begin to have fun.