Which artifacts are best to equip a hero with?

Zubr, but there are only four pockets!!! Where will you put the fifth arrow??? :D

You can change equipment during the battle, or rather, before it (hee-hee).
There is no ideal equipment. I carry a whole wagon of junk with me, changing items as the game progresses (at the beginning, I carry items that act as treasure chests, like a minecart with ore).