For a relatively lower model count game, there is a pretty good, official list for Of God's And Mortals if you want to go that route with more fantastic elements.
There is also the Kings of War Historicals if you want to have more variety in your opposition, mainly because it's more of an open play thing from where I've seen it run...
I've mainly stuck to skirmish games though, however, there are a lot of people that I know who take a skirmish rule set and multibase for it and up base size for everything, which tends to work rather well with Ronin from the few bits I've played that way.