I re-worked the relay board a bit while I'm awaiting for a few more parts to arrive. Hopefully the poly fuses and PET covering will show up this week. Once I have everything laid out I'll start soldering.
I ordered samples of male and female solder cup DB-37 connectors but I think that I may switch to the Molex 20 pin ATX connector. I found a piece with a little over 12" of 18ga wire in my electronics junk box. I think that this looks better than the db-37 and would handle more power too.
Just off to the right in the pic you can see my free sample project box that I'm going to use for my wide-band O2. When I'm done with the relay board project I'll post up re-work pics of my wide-band O2 project.
Warm weather is just around the corner and I can't wait to get started up in the garage again.