Not sure how high of damage you're looking for but a
Bloodforge Hammer is a very easy quest for a non-evil cleric. Wiki says level 10 but the guy you need to kill is a single pull level 5 wimp with a filthy mouth
If you're feeling lucky you can head over to Kithicor and see if one of these is rotting, which does occur from time to time:
http://wiki.project1999.com/Tainted_...n_Morning_Star
http://wiki.project1999.com/Ruined_B...n_Morning_Star
What I did was camp Dyllin for the Testament of Vanear (great quest you should do in your 20s, soloable) and asked some people in kith give me a heads up when a star dropped.
If you're dead set on buying a weapon a
http://wiki.project1999.com/Sharkbone_Warhammer or like item should fit the bill nicely, a
http://wiki.project1999.com/Smoldering_Brand would do more damage but tbh you'll get more mileage out of something with wisdom on it for when you eventually outgrow melee.
Good luck!