B. Possibly go back and give Civ 3 another chance. Though, I liked what I played of the Civ 4 demo.
I tried to like Civ 3 more than once. A year after I first tried it, I tried again and I just couldn't warm up to it. Once I tried Civ 4, I never looked back.
I agree with Lord Parkin's suggestion that you get simply Civ 4 and BtS. If you do, I bet it'll be more than a few months before you think about playing Civ 1 or 2 again.