I really need help. (Hopefully with a Herbie style drain)

[sphelps]

This is a general drawing that should hopefully give you the idea. First you can use a 1.5" drain and a 1" drain. I would advise using the 1" drain as the primary and the 1.5" as the secondary (back-up). If you want you can use a standpipe with the secondary line, most people don't but it will keep things quieter if it gets used. You can use any type of standpipe, doesn't have to be an HGB as shown.

The siphon tube is not required but will prevent the overflow from draining when the power is cut.

The one thing I wouldn't do is tee both drains together at the bottom, keep them separate.