I have both for my Simrad go9. I really don't like the C-map compared to the Navionics but it came with the purchase. I'll let you have the C-map for $20 if it works for you. You gave me a smoking deal on that camper shell so I owe you one.
I'd pick up the Navionics Platinum+ 644P+ card. It covers all of Southern California and Baja and will have SonarCharts Shading available starting on 6/14. Navionics has it on sale for $99.50 right now. Here is a link to the card.