The iPad 4, or Mini has a capacitive screen like Apple's other iPad's or iPhones. So yes, stylus pens will definately work on it. Actually, it is good practice to use a stylus once in a while, because they don't smudge the screens lik human fingers do.
You can find ipad stylus pens in many places online and in stores. Generally online is cheaper, but you have to wait for the delivery. If you're gonna get it online I recommend getting from a site within your own country. I once ordered a stylus pen and , well, 50 days later it still hasn't arrived.
But these guys are good if you're in Australia The Stylus Stall