It does not matter what wheel you buy, 20-24" can all be, and are all balanced from the factory. If you are worried about balancing issues, DO NOT BUY CHEAP TIRES!! For the last 5 years I have mounted and balanced tires from every brand and size. Michelin and the newer GY Fortera and Silent Armour are primo. Just because they run a buy 3 get one free special, doesn't mean you are getting a deal. I have replaced tires within 10,000 miles because of poor quality and lack of rotating. Do your research!
Balancing is also an art. You get what you pay for. The *Free Balance and Rotate* with oil change will get you an unbalanced wheel 90% of the time. Take your investments to someone credible, someone who has the right equipment, and someone who knows what they are doing. Also, keep em rotated no longer than 6,000 miles, less if you are doing alot of towing.