Kingmaker are slightly chunkier than figures from the Agincourt range, still they mix well. Apart from usual differences in sculpting (and some minor errors in armour design) Claymore are indistinguishable from those Perry minis. I've mixed all of them, if for earlier period engagements.
That said, among German knights of at least the 1420s to 50s the so called
Kastenbrustharnisch was quite common – but I've only seen it sculpted once (on order by Steel Fist Miniatures IIRC). Apart from that, plate armour wasn't as widespread as in France or England; many people would rather continue the use of mail and organic armour and add plates to it (arms and legs in particular). High-ranking nobles and princes would, of course, rather wear armour imported from Italy (often appearing quite like later designs) or, increasingly, produced in Germany/Austria/Bohemia itself.
I would avoid obvious English styles like steel collars or distinctly later designs like sallets or fluted/Gothic armour. Other than that there's not much to choose from, unfortunately. Therefore I'd rather go for the early part of that conflict and run with Kingmaker, with Perry Frenchmen and well-armoured Claymore figures thrown in for good measure.
Just a word on the Hussites: These weren't your average untrained peasants but rather well-organised militiamen, often recruited from urban communities and even from the nobility, so not necessarily poorly equipped. Therefore almost any Kingmaker figure is usable for both sides of the conflict.