Bretonnia

As Bretonnia is basically a historical human army, there should be many alternatives among historical wargames and heroes basically everywhere (I didn't even try to find all the possible historical manufacturers). Gamezone also has a feudal knights range that seems to be exactly this. My favourite damsels and foot knights are probably from Darksword, but there should be many hero options as they are, again, just medieval humans.
I haven't been able to find any full model that would work for Grail Reliquae, but many people just convert something simple.

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 Round Table (and other sources) 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

Knights Errant/ Knights of the Realm
Gamezone Feudal Knights
Fireforge Games Teutonic Knights
Perry Miniatures Agincourt Cavalry (and some more)
Gripping Beast Military Order Knights (and more and command)
Gripping Beast Teutonic Knights (and command)
Gripping Beast Crusading Knights (and some more and command)
 
Men-at-Arms
Scibor Town Guard

Gamezone Armed Retinue
Fireforge Games Foot Sergeants
Mantic Basilean Men-at-Arms
Wargames Foundry Spearmen in Gambeson

Peasant Bowmen
Gamezone Feudal Bowmen
Wars of the Roses Infantry
Wargames Foundry Archers Firing


SPECIAL

Grail Reliquae and Battle Pilgrims - Many people convert their own (sorry if this is not user-friendly enough)

Gamezone Conscript Peasants (or use any of the Men-at-Arms models)
Hasslefree Tiriel for the Reliquae itself (also a kneeling version)
Reaper Clergy, for actual holy pilgrims
Reaper Battle Nuns
Mantic Basilean Sisterhood
Reaper Medieval Sarcophagus for the reliquae
Darksword Woman Emerging from Water, as a statue of the Lady?

Gripping Beast Crusading Pilgrims (and command)


Mounted Yeomen
Perry Miniatures Light Cavalry
Gamezone Mounted Squire (and more)
Reaper Paladin on Pegasus
Gamezone Elf Winged Cavalry
Reaper Pegasus wings bit
Gamezone Pegasus of Light

Questing Knights 
Gamezone Knights Errant
Gripping Beast Teutonic Knights (and command)

RARE 

Field Trebuchet
Fredericus Rex Trebuchet
Fenris Games Lazy Trebuchet
Perry Miniatures Bombard, also useful for crew alone
More possible crew by Perry Miniatures
Gripping Beast Trebuchet

Grail Knights
Gamezone Feudal Knights

Gamezone Grail Knights
Mantic Basilean Paladin Knights
Raging Heroes Mounted Knights (on Kickstarter)

 LORDS AND HEROES

 Lord and Paladin on Foot - I love the whole Darksword ASOIAF range. Bellow are just some of my favourites.
Darksword Loras Tyrell
Darksword Young Robert Baratheon
Darksword Jaime Lannister
Darksword Tywin Lannister

Mounted Lord
Darksword Mounted Ser Loras

Gamezone Feudal Lord
Reaper Sir Daman
Reaper Lady Jehanne
Mierce Miniatures Vagrant Knight

Damsel on Foot - many lovely options, bellow are just some of my favourites.
Darksword Lannister Lady in Waiting
Darksword Female Mage with Staff
Darksword Young Lady in Waiting
Gamezone Learned Sorceress
Custom made minis Sorceress (also check out others, this is just my favourite one)

Mounted Damsel
Gamezone Mounted Sorceress
Reaper Lady Devona

Fay Enchantress - not a simple damsel, so deserves a different model. I really love this one:
Darksword Tam Lin

King Louen Leoncouer

D&D Miniatures Hippogriff
Black Tree Design Hippogriff
Ral Partha Hippogriff
Ral Partha Hippogriff
Mirliton Hippogriff
D&D Miniatures Arcadian Hippogriff

Gamezone Veteran Griffon
Reaper Griffon
Titan Forge Grandmaster of the Lion Order

I also recommend going through the whole Gamezone range (there are models I haven't linked), whole Darksword G. R. R. Martin range, Mantic Basilea range, Wargames Foundry medieval range, the new Raging Heroes TGG2 Kickstarter, Wargames Foundry Barons Wars and historical manufacturers such as Fireforge games, Perry miniatures, Warlord Games, Fredericus Rex and others.