I would like to make Android think it has a SIM card in it, and change all of the info about said SIM card. I have an Android x86 ISO I can use. Any ideas?
Welcome to the forums. Why do you need to change the SIM info. I think you need root access for most of that anyway. What are you using the Linux ISO for?
But the only reason you'd need a SIM is to make (or take) phone calls or texts, which you can do with Messenger for Google™ Hangouts in Firefox, you don't need Android x86 for that..