I finally sat down and called the vinyl vendor - she gave me the warehouse number to call on Monday. I've decided that if they can get gunmetal gray I'll use that for contrast over black; failing availability I'm going with either olive or hunter green (crossing fingers - PLEASE have what I need when I call back Monday!)
Meanwhile I'll be twitching a bit because I hate to wait to start a project. I'll probably use the time to clean up/vacuum the sewing area.