Do you know if I can use another form of 'shapefile' that has nicely formatted labels (I'd be willing to purchase it)? Yes, I was afraid I will have to resort to buying MapText.
There's other file formats that do support text to a certain degree, but I can't think of a reason why you should have to buy a dataset that has nicely formatted labels if you're only going to do counties (if there even is one available).
Your comment regarding updates piqued my interest, because US counties are not known to change all that often, once you've labelled them you can simply reuse those labels all the time. In order to make a better suggestion, I think it would help us if you could elaborate a bit more about the kind of maps you're making and exactly what is going to be updated over time.