Lodge is the only USA company making CI cookwear, and USA-made is the only CI I will buy.
Around here, it's my wife and I and I use an eight-inch Lodge skillet on my Performer. I also have a two-quart Lodge dutch oven that gets a pretty good workout. There are times, however, that I wish it were bigger.
Going through this site to Amazon is a good as way as any to buy CI, and if you have Amazon prime, shipping can be free.
Since cast iron can last forever, there are lots of old pieces available on Ebay and the Goodwill store and possibly your local thrift stores, but shipping gets expensive. Wagner and Griswold are two popular brands of early cast iron. But they can get pricey since collectors are buying those pieces, too.