I have used 3 company's that supply mannequin heads and honestly all 3 heads were fantastic quality and great to work with.
Mannequin Doll Recommendations
All of the following mannequins have 100% real human hair.
Before buying, Google discount codes , you may get a better deal than what is on the website as thy often give out codes.
L'image seem to be the most popular, I have Louisa £210 she is a competition mannequin head so is a bit more expensive that a regular dolly head.
Pivot Point also do great mannequins, I have Ingrid £165 but found her hair a little short and ended up getting extensions to use with her.
K-Dolly by Kasia Fortune is my latest mannequin head it's a lot more expensive at £345 plus custom charges from UK but it's fantastic quality and the hair is so so thick. She also has shoulders so if you were taking pictures for your portfolio you really can't tell it's a mannequin from the back!