Just an update that I got this resolved. To use this display on an Arduino Micro, the appropriate setting is:
U8GLIB_NHD27OLED_GR u8g(15, 16, 17, 9); // U8GLIB_NHD27OLED_GR(sck, mosi, cs, a0 [, reset])
I haven't tried hardware SPI yet, but I don't have any reason to believe it won't work.