My first Eclectus was a male though, and I still have Kiwi who is the patriarch of my aviaries. Please do NOT buy an unweaned baby. It can be a death sentence for the bird and if you want your baby to have the very best chance of being healthy and well adjusted, leave the job to someone experienced. In answer to your question about Eclectus parrots being mean, each bird is very much a unique individual with its own personality. They are generally laid back and good natured birds.
Early socialization is important.
Any parrot species can be unpleasant if improperly managed in the first formative months. If you find a good breeder with a good reputation, your baby probably will be properly cared for, abundantly weaned, and will be a happy trusting creature. Then you will be as madly in love with the Eclectus as those of us who have been under their spell for many years. I am thinking of getting an Eclectus. I would love to hear your personal experiences and any advise for the first time Eclectus owner.