Unfortunately there's no way to change the ATC in 2002. You can add callsigns, but that's about it, it won't get any more detailed than that. In 2004 it's a little better with more ATC like step-climbs and general improvements all round. I don't have 2004, so I'm not sure just how improved the ATC is.

For the best ATC, you should consider flying online. Register over at www.vatsim.net and get started there. It's kind of complicated at first, but eventually you get used to it and it's fantastic. Nothing beats flying online with live ATC at the other end.

Apart from maybe flying in real life, but you're not going to be fined or have your licence taken away from you on vatsim!