But which one?
Global Sun Oven - Solar Cooker - This one seems to be widely accepted as one of the best solar ovens available. It gets high marks at all the sales/review sites and is widely used around the world. This seems to be the solar oven of choice for most global hunger charities. The downsides are it's expense ($220-$270 depending on where you buy) and size/weight (21 lbs) and it doesn't come with any cookware.
Scott Resources Portable Solar Oven - This one is inexpensive enough for sure. It is also small and light. The reviews however aren't very kind. General consensus seems to be that this is a great inexpensive way to try out solar cooking, but if you want something that will last you need to spend a bit more.
Solar Oven Cook Food Using the Sun - This one appears to be so compact that a hiker could easily carry it in a backpack. It's very inexpensive and lightweight but I think it's intent is more for backpackers or tent campers rather than any serious solar cooking.
One company has taken the novel approach of making a hybrid solar oven. This looks like a nice setup and gives you the option of using the 120 volt as a backup should the sun leave you high and dry. I also like the self-contained solar-suitcase appearance of the product. All-in-all it looks like a really good oven for a full-time rv'er. The only downside is the price.
And that brings me to this one, the Sport Solar Oven. It is large enough to cook most anything you would want to cook in a solar oven yet not so large it cannot be stowed in an RV. It's light weight (11 lbs), inexpensive, made with recycled soda bottles and aluminium and comes with cookware.
I'm going to keep researching a little more before making my decision. If anyone out there has any experience with any of these or any other solar ovens, I would be very interested to hear from you.