I would simply use the stats for a greataxe, but make it blunt damage. After all, the stats for the warhammer and battle axe are the same except for damage type.
The weapon stats you post above are overpowered for a non-exotic weapon. Every PC that wields a two-handed weapon would take it if it was available like that.
I'm not sure what you mean by "normal" either, but the Forgotten Realms Campaign Setting has a listing for a Maul that is a martial weapon, two-handed, 1d10 x3, 20lbs, bludgeoning. I use that.