Beastmen

Beastmen were one of the armies where I expected more problems and what saved the most when compiling this list were the amazing Mierce Miniatures (I am just worried about the price tag for such an army). Other than that, Crocodile games were very helpful and Reaper and Gamezone seem to be the best sites for anything.

A few comments first:
  •  The models listed here are not perfect and many are not on the same level as the original ones (those are usually way older than the current GW range). I am not saying losing GW models won't be a pity, if anything this work is making me appreciate them even more. I am just saying that a solution exists. The important part is, the models are out there.
  • This is not only my work. I have used ideas and suggestions from The Herdstone and am very grateful to all the people there and their collective wisdom.
  • In many cases I was unsure about the size of the models and was forced to go on guesswork only. I hope at least some of them will work.
  • When possible, I have tried to link to groups of models and larger units, if only to show multiple sculpts at once. Most of the companies sell the individual models as well, should that be preferred.
  • I am quite a chaotic person and may have overlooked something awesome. I usually try to link sites that offer greater number of useful models or the ones I know I have not exhausted, but searching around the linked models might yield even more fruit.
  • If you know about something useful not linked here, please let me know and I will add it. This is by no means an exhaustive list and can never be, but I would like to list as many possibilities as possible.

CORE

Chaos Warhounds

Mierce Miniatures Hounds of Carn Dhu
Crocodile Games Wendigo Howler (and one more)
Reaper Hyena Pack

Avatars of War Dire Wolf
Heresy Miniatures Hellhounds

Reaper Hell Hounds
Grendel Hellhounds

Gor Herd
Reaper Satyr Warriors
Reaper Reven Woodcutters
Reaper Reven Beastman Woodcutter
Reaper Urga, Reven Sergeant
Reaper Traeg, Reven hero
Black Tree Design Beastmen Elite Fighters (and more)

Tuskgor Chariot /Razorgor Chariot

Gamezone Horned Beasts Impact Chariot
Grendel Razorback Chariot

Ungor Herd/ Ungor Raiders

Crocodile Games Satyr Archers
Crocodile Games Khemru Slingers
Reaper Satyr
Black Tree Design Beastmen Warriors (and more)

SPECIAL

Bestigor Herd

Mierce Miniatures Gabrax

Centigor Herd

Mantic Abyssal Dwarf Halfbreeds
Mantic Abyssal Half-breed Lord
Otherworld miniatures Centaur Patrol
Reaper Centaur Warrior
Reaper Chiral, Centaur Captain
Reaper Lamia Priestess

Harpies

Avatars of War Harpies of Apocalypse
Mantic Abyssal Dwarf Gargoyles
Reaper Reven Harpies
Otherworld Miniatures Harpies (and one more)
Otherworld Miniatures Gargoyles

Minotaurs

Avatars of War Minotaur Lord
Avatars of War Minotaur Lord
Mierce Miniatures Ckaarakk
Mierce Miniatures Tarvax
Rusted Heroes Taurus
Scibor Miniatures Minotaur Warriors Set
Reaper Minotaur (also in Bones)
Reaper Trezzna (and some more)
Spellcrow Minotaur

Ragorgor / Razorgor Chariot

Reaper Dire Boar
Reaper Krungbeast
Tabletop Art Giant Boar Set

Hell Dorado Jaws of the Deep

RARE

Ghorgon

Mierce Miniatures Galagaak
Mierce Miniatures Angalaak
Maxmini Immortal

Cygor
Maxmini Cyclops

Giant
Mierce Miniatures Gromi
Mierce Miniatures Magágg
Mierce Miniatures Cormorágg
Mierce Miniatures Gomagg
Reaper Nor'Okk, Ettin (also in Bones)

Ultraforge Giant
Blood Keep Miniatures Garguth

Jabberslythe
Mierce Miniatures Jabberwocor
Hordes Everblight Archangel
Reaper Jabberwock (also in Bones)
Reaper Dragon Nachtlufte
Reaper Verocithrax
Mierce Miniatures Gynroch ap Roch
Iron Wind Jabberwock

Spawn of Chaos

Reaper Eye Beast (also in Bones) (and one more)
Reaper Gug, Eldritch Horror
Otherworld Miniatures Otyugh

CHARACTERS

Beastlord / Wargor

Avatars of War Beastman Warchief

Mierce Miniatures Chaagmuth
Mierce Miniatures Brunchaath
Mierce Miniatures Daachuch
Hordes Maximus

(Great) Bray Shaman

Mierce Miniatures Aanchuth
Gamezone Shaman Horned Beasts
Reaper Darkspawn Goat Demon

Doombull / Gorebull

Mierce Miniatures Praach
Hordes Gnarlhorn Satyr (and more)
Yedharo models Capricorn
 
I also recommend going through the entire Mierce Miniatures shop, especially the Fomoraic section, Crocodile Games, especially Khemru and Hyberborea section, a search for Reven on Reaper website (plus the obvious ones like beast, minotaur, giant and so on) or the Hordes Minions range.
And of course the alternative model threads at the Herdstone, from which I took many on this list: here and here.