IMO you shouldn’t spend money on new technologies like Blu-ray until you’re actually going to use it, because there will be cheaper better faster drives available. This is the way it has been with other technologies and it will be the same with Blu-ray.
If DVD quality scanning is your main objective, you should get a LiteOn DVD burner. They aren’t good for CD scanning however.
If CD quality scanning is your main objective, I suggest you get an Optiarc 5100/7200/7200 series drive. They can also be used for DVD scanning, but it’s unclear how well they do this. I’m fairly sure an Optiarc 7200S would do better at DVD scanning than a LiteOn DVD burner would do at CD scanning, however.
Or do like many others do - get two or more drives that complement each other well.