I believe that Warlord games make plastic Greeks, and Macedonians. And I think Victrixe mins is starting a Punic war line of plastics.
Yes they do. The Macedonian phalangites could be converted easily to Successor phalangites, but for Thureophori, cavalry and elephants etc. you'll need to go metal. For the Pontics you might get away with the Macedonian pikes, but there are hints they might have looked more Eastern. And who knows what their "Imitation Legionaries" looked like.
The classical Greek Hoplites that Warlord took over from Immortal wouldn't be suitable for a Republican Roman opponent if you want to be picky about it. The Greek military system had gone through a change by the time the Romans arrived.