We used to have a sticky for people to ask this question as many times as needed. I think it died sometime after the spreadsheet came about, when people started doing their own number crunching.
Me though, I just remember my
handy table of weapons and trust my gut. Too lazy to actually crunch the numbers (now... if the spreadsheet read input from character dumps, and crunched for you- without needing to enter all the info first...).
First choice:
Demon whips are faster, hit harder, and have a cheaper minimum delay skill than maces. The +5 alone does not make the mace better. If you're a primary caster though (ie, mele ain't the deciding factor), the +5 int and +5 AC over your robe might well be worth it. The demon whip is your better option for damage, but feel free to hold on to the mace to toggle to if you need the int boost, or Sinvs. Reaching isn't the best brand in the world, but it is versatile- especially as a necromancer with things to hide behind! Enchant it if you like, although you might want to wait and see if any hell knights drop a better branded demon whip.
Second choice:
That *Tele, and -3 are not worth the +10. I'd stick with the sling.