Monsters got to have teeth, so I'd pick the 2nd gen, especially a J model.
As far as accuracy, I've seen up to ±45 seconds per day.
I don't think the Orange Night Monster is a rare watch, but it might be hard to find and process are going up lately from what I've seen, especially for J models.
The last two pics are probably both Baby Monsters as I don't think any regular Monsters had the Seiko 5 logo. Seiko 5s are considered "sports"watches and usually aren't actually dive watches. They usually don't have a screw down crown or more than 100m depth rating.
If you know what you're getting, a Baby Monster can be a good deal, especially in today's Monster market, but I'm partial to the 2nd gen ones myself