YMMV on this, but try logging in to your Citicards online, and look at your balance transfer offers. All my citi cards have a 12 or 15 month 0% APR offer on balance transfers AND new purchases. The fine print shows that if I accept the offer, any new purchases received the 0% APR offer as well, and no balance transfer is required. It's just an option.

As far as converting, I tried to change my old mtvU card a while back and they wouldn't let me. But I know some people have had success.