Hi Lisa, I can certainly relate to the stress you are feeling. I was diagnosed about a year ago and spent the next three or four weeks researching, thinking and talking about my AN on a non-stop basis. Not so fun, but an essential part of the process. My AN is 2.6 cm or so, and I elected to go with Cyberknife. I've described my decision making process in detail in the website below. I never considered Endoscopic Surgery, but I checked out the SBI website and it does look interesting and worth looking into. I would find out what you can about your options and then set up consults with neurosurgeons who specialize in each. One unusual thing you'll find about the AN universe is that there's considerable debate among neurosurgeons about how best to treat smaller ANs like yours. They tend to be on "teams", with microsurgeons supporting surgery and radiosurgeons supports radiation, etc. So it's good to get different perspectives when researching the options.
Good luck and keep us posted.