Noobs questions. Request guide for 2 handed Sunder

Hello fellow Exiles, i am a noob who play Marauder until level 81. My main weapon is 2 handed mace, Sunder for main attack.

Please look into my build and passive skill tree and do provide some advice for me to improve my character.

This link to my build -> www.pathofexile.com/account/view-profile/Rosli_2252/characters

I have no idea what to choose for secodary weapon or attack. Interested to dual wield mace for sunder but somehow the dps seems a lot lower then 2 handed mace i currently use.

Please also provide some suggestion regarding that.

P.S. This is the first time i ask in PoE forum. Apologize if i made any mistake.