Your best bet for a test bench is a harness with a 4-pin (colors and ground) and 2-pin (syncs) with a quick connect between the two syncs to change it from composite sync on both pins (for monitors like G07) and composite sync on one pin (for monitors like K7000).
Then you can move the 2-pin sync connector between positive or negative, depending on the monitor or board you're testing.
I have one of BobRob's video extension cables, which helps me keep my test board and harness in one spot, and am able to connect the video to a monitor either on my bench, in a cab, or on the floor.
There are a few weird connectors (20EZ, Nanao, Toei) that have different sizes and pinouts, but you can make adapters that go between your "normal" connectors and the strange ones...