Places online like autoanything.com and a few others would probably have the best deal on the Husky's.
Personally, I have and would recommend the WeatherTech Digital Fit liners. They're a little pricey (about $200 for front and rear) but they are worth every penny. They provide a little better coverage than the Husky's and the fitment is awesome.

As for vehicle protection with the power boards...you may want to see if anything is available for the Navigator. The Nav comes standard with power boards and I believe there are a few options out there for them.

Google might be your best friend in either case.

Good luck and post pics of the new ride!