Your questions, my answers:
Q1) "can i request on their side anyone i want to appear in court?"
A1) Once the suit is properly filed, you can subpoena or request deposition of any relevent person on the opposition.
Q2) "can i sue for mental anguish?"
A2) Probably not. Most Small Claims actions provide for recovery of specific damages only, and are not provided for mental anguish.
Q3) "can i sue for slander and libel?"
A3) Possibly. It depends entirely on the circumstances and the evidence that you can present.
Q4) "how would i find out where to send a subpoena to?"
A4) You would have to serve on the Corporations 'Agent for Service'. This person can normally be located through your states Business Regulatory agency (Secretary of State).
Q5) "are there any lawyers in illinois i can talk to that can help for a low price or for free?"
A5) 'Free' is unlikely.... and how much is 'low price'???
You will need to find someone, if available.