For custom heads (and parts) for 6 inch figures. I am not vouching for any of these sites. Well, except https://www.outerrimtraders.com/. I have used them a number of times.

• https://www.outerrimtraders.com/
• https://castingcave.ecrater.com/
• https://www.twosunscasting.com/
• https://scoundrelsstock.bigcartel.com/
• https://www.planetarydogtoys.com/shop
• https://www.wolfkingcustoms.com – only sells stuff periodically