Which roof rack to buy?

OK, Call me paranoid or not but I plan to take my 2009 Prius (Generation 2) to Alaska next year in the summer, and I never leave home without two (not just one but TWO!) full size spare tires which I prefer not to carry inside the vehicle. So I had the idea of purchasing a Thule type roof rack and mounting an XCAR Roof Rack Carrier Basket with dimensions of 43" long x 39" wide x 6" high. This will fit two fully inflated spare tires (type 185/65R15) on top of the car in the XCAR basket each located at adjacent diagonal corners.. XCAR was chosen since it has the deepest dimension that I could find of 6" high. Then I have an idea of incorporating my yet to be designed idea to mount together two Renogy Eclipse 100 Watt Monocrystalline Solar Panels (dimensions 40.9 x 21.0 x 1.4 inches) to form a near perfect fitting cover that when in use can pivot upward on an angle to maximize the sun collection angle, and when in transport will lay flat to form a cover of approximately 42" x 42" which will almost perfectly cover the tires and protect them from the sun's UV rays, as well as lock them down to prevent theft. The tires are 7.28 inches wide (or high in the rack) so I will add additional mounting hardware probably using 1.5 inch aluminum "L" channel to mount the solar panels to the top of the XCAR rack. It will be somewhat drag intensive so it will probably reduce the MPG by 10 to 20 percent at highway speeds. However, I will not have to worry about protecting the tires in the wilderness of Alaska, or for that matter charging my lithium battery in the car. If anybody wishes to give me feedback on this proposed idea please speak your mind because I value your opinion. I will post my final design and photos within the next few months.