I've read Suicide Island a while back until I was up-to-date at the time, that fits the bill. It's by Kouji Mori, who was a close friend of Kentaro Miura and is now involved with the continuation of Berserk as far as I know.

Besides that, I probably don't need to tell you that Vagabond and Vinland Saga are excellent. Lone Wolf and Cub is also really good in my opinion, albeit pretty old by now.