If upkeep isn't an issue for you then the warhammer would be fine. Personally I use cheap, fast, and short 1h weapons if I'm using a secondary at all. Won't need as much proficiency in it that way to be effective. There is no best weapon by any means, just use whatever you want to use and try different things out. The dao weapons are good as backups, but so are the thrust ones like the scottish and the other 0 slots. It's all preference!