Warmaster is a great ruleset for large scale fantasy battles. As such, the fact that GW has stopped producing 10mm miniatures shouldn’t stop existing or new fans from playing the game. And even with ebay prices getting out of control (especially for the more exotic races of the game) there are many providers of 10mm fantasy and historical miniatures to help you collect your new warmaster army.
Below we try to list some of the the options available for the Brettonians army based on the warmaster troop types. This is one of the easiest armies to field due to the large portion of the army being essentially a non fantasy army (in terms of troop types).
TBLine TB4170 Heavy European infantry
TBLine TB4179 Armed peasants
TBLine TB4164 Teutoni Knight
Kallistra HA-06 Trebuchet
Enchantress on Unicorn
Woodland Creatures [400FAN19] includes a suitable model
Notes: Credits to the participants of the post on the Specialists arms forum that discussed the above topic