hm, quite honestly any flat iron with rounded edges will give you curls! you can get a nice cheap conair from wal mart on the cheap for less than $30. just use a lot of heat protectant on your hair to keep it nice and healthy!
even better, you can use velcro rollers for curls. pop em in, blow dry, let them set, take them out, tousle/add spray, and bam, hot and sexy hair. =D