I think that gunplummer has this one nailed for a thumbnail summary.
Personally, I've had both type 38, 6.5mm, Arisakas and Type 99, 7.7mm, arisakas. I liked them both. I'm taking my T99 elk hunting with me this fall.
I don't know much about the Steyrs, but I can't imagine that the on line support for Steyr runs deeper than for Arisaka. There are a lot of people that want to see these rifles keep humming. Ammo for the Arisaka isn't like finding sand in the sahara, but it's not hard to find nor find info for reloading. I have only seen one source for the Steyr 8mm rimmed ammo.
Take your time, do some research and find a solid Arisaka that will last.
I'm right about the metric system 3/4 of the time.