Just like this guy the 10 was easy to handle and good for 2 people. 12 is heavy but works well for my family of 4. Also the 12 is a bit big for my the large burner on my stove top. The 10 fit perfectly. All my stuff is lodge and has worked well. I think Costco might have a 2 skillet pack. Not sure of the brand.Consider that a 12" cast iron skillet can be rather large and heavy. Good for things like frying chicken, maybe, but otherwise a bit unwieldy. I think the 10" size is the sweet spot.
Skillets do not usually come with lids. You can borrow a lid from another pot, though. I like the clear glass ones.
Older cast iron can be reconditioned to be like new. Some of the best pans are the older ones.