Federal Aviation Administration - Designee Locator
I think all ATP examiners can do SE. But they are restricted to specific ME types, which are listed for them. As previously stated, fixed gear was fine (well, 20 years ago anyway), just need IFR equip.
Find a school in an area that you want to do it at, and have them ask one of the examiners they recommend or contact the examiner yourself. Most have probably never done a SE, but should be willing to give it a try.