Okay, I'm the odd one out. When camping, I don't want to have any left-overs (or, in camp terms, waste). I find the 10" DO too large for most things, and like the 8". My camp frying pan has also been an 8", although this year I have moved up to a 10". A small desert or side veggie can be done in a 6" DO, and was plenty when my twins were younger. Now that they are teens, admittedly I may move up to one 10" DO (main dish) and an 8" (bread or desert), or maybe 2 8" pans. A 10" or a 12" would be good for pot luck dinners if you plan to attend teardrop gatherings, though.
So, really, how many are you planning to cook for, and what size pans do you usually cook in? Do you plan to bake bread with your meals? Baked desert? Do you prefer stir-fry meals or one-pan/casserole meals? Vegetarian casseroles are easy in DOs, so are rice/quinoa to go with a stir-fry. Potatoes can be wrapped in foil and cooked in the coals, either under the frying pan or on the lid of a DO with the coals heaped there.
You've already mentioned pancakes. I suggest a round griddle (comal, if you live in the southwest).
http://smile.amazon.com/Lodge-Pre-Seaso ... nd+griddleIt is MUCH easier to flip a pancake when you don't have to dig for it and fight the sides of a frying pan. I also use it for frying eggs and cooking crepes and tortillas.
Dutch ovens come in a lot of sizes. 6" diameter holds 1 qt of contents (up to the brim, likely to slop if you really fill it all the way up); 8" diameter holds 2 qts; 10" holds 4 qts; 10" deep holds 5 qts; 12" holds 6 qts, 12" deep holds 8 qts.
http://smile.amazon.com/Lodge-Camp-Dutc ... dutch+ovenFor comparison, a common bread pan is usually a 1 qt pan. A 9x13 pan (used in larger households than mine for sheet cakes, lasagne, church casseroles, etc) holds 3 qts. My go-to sauce pan for a main-dish soup is 2 quarts (again, filled to the brim, which I don't do), and that more than fills the three of us up. Think about your go-to pans and figure on DOs of similar size. You can see I keep coming back to a 2-qt pot as my basic cook pan, which is why the 8" DO works so well for us.
I have a modern Lodge 8" skillet, and it is perfectly fine. If I had never used my grandmother's cast iron, I wouldn't have known that the vintage stuff is so much better. I picked up a modern Lodge 12" and a vintage Lodge 10" at a Goodwill, and then found my other grandmother's 10" vintage Griswold in a shed on the family farm. Well-seasoned, the modern ones will be nearly as non-stick as the older ones, but the vintage ones have really smooth cooking surfaces that are, well, a joy to cook on. The vintage ones also tend to be just a bit lighter weight than the modern ones of the same size. Grandma's Griswold is now my go-to skillet. I can cook a frittata in it, and it will just slip right out in one piece for serving. Nice. Anyway, you can start with a Lodge skillet and keep an eye out for some vintage CI later. (Unlabeled pans are less expensive, Griswold and Wagner pans can get quite pricy, especially if you are buying from a cast iron reseller. You can still find the occasional yard sale or Goodwill bargain, but there are a lot of collectors out there searching those same locations.)
And then there are the extras. If you like to cook pasta, rice, or other grains with your meals, and you don't plan to cook over a fire or coals, any pan will do, and will be less likely to rust. I have some old aluminum camp pans, which are also used to heat water for washing up.
Oh, and we like waffles as an alternative to pancakes. We have one long-handled waffle iron for cooking over coals in the camp fire
http://smile.amazon.com/Romes-1405-Waff ... affle+iron, and another short-handled waffle iron for the camp stove
http://smile.amazon.com/Romes-1100-Fash ... affle+iron.
Anyway, don't just go out and start buying cast iron without knowing how many you are cooking for and how you are planning to cook. Take a look at the recipes on this site ("Recipes by and for Teardroppers" and "T&TTT Cookbook #2") and at
http://camp-cook.com/forum/index.php. Try a few camp recipes at home, either in your kitchen or in a firepit outside.
And finally, you can camp without cast iron cookware. I grew up camping with my parents (even have pictures of my mom at a campground picnic table trying to feed a toddler and a baby and visibly pregnant) and my dad (the camp cook) only used aluminum pans and a non-stick aluminum griddle on a Coleman camp stove.
Happy Camping!
Catherine