The figures you have all look look fine - the only one which isn't perfectly suited is the pointing figure on the top row in black - the long, split, chainmail is a much later style, as are the chainmail leggings (char-something or other). That said, the Helmet is spot on and looks fine. Personaally, I'd stil use him, although I might file the legs down to look like trousers.
For inspiration - these reenactors are spot on your period, and are about as authentic as they come (90% of the kit is based on reproductions of finds):
http://www.wulfheodenas.com/For the gripping beast plastics - the helmets with cheek guards are definitely fine. I'm not sure of the dates that the 'nasal' spangen helmet came into use, but you should be ok with mixing a few in.