the halberd and the needle pistol are easy.
halberd
http://uk.games-workshop.com/storefront/store.uk?do=Individual&code=9947010700209&orignav=10
the needle pistol
http://uk.games-workshop.com/storefront/store.uk?do=Individual&code=9947010800302&orignav=10
the head is a bit more problematic but id go for
http://uk.games-workshop.com/storefront/store.uk?do=Individual&code=9947020806504&orignav=13
though personnaly i don't like the idea of the head and would go for either
http://uk.games-workshop.com/storefront/store.uk?do=Individual&code=9947010207501&orignav=10
or take a normal plastic head and dip it in plastic glue so that onlyone side is covered then let it soften then gently draw your finger down (wear latex gloves for this) this side of the face pulling the details out of proportion, this would give you a better mutation look in my opinion.
halberd
http://uk.games-workshop.com/storefront/store.uk?do=Individual&code=9947010700209&orignav=10
the needle pistol
http://uk.games-workshop.com/storefront/store.uk?do=Individual&code=9947010800302&orignav=10
the head is a bit more problematic but id go for
http://uk.games-workshop.com/storefront/store.uk?do=Individual&code=9947020806504&orignav=13
though personnaly i don't like the idea of the head and would go for either
http://uk.games-workshop.com/storefront/store.uk?do=Individual&code=9947010207501&orignav=10
or take a normal plastic head and dip it in plastic glue so that onlyone side is covered then let it soften then gently draw your finger down (wear latex gloves for this) this side of the face pulling the details out of proportion, this would give you a better mutation look in my opinion.