And unless you have uber crafting levels for Cannith Crafting, that deathblock item is going to be armor, almost exclusively. I’ve been checking the AH on my server, and cannot find a Deathblock necklace to save my life. They used to drop. Now it is like they fell off the face of the earth.
For potions you should ALWAYS carry:
100x of remove curse, remove disease, neutralize poiton, lesser restoration, remove blindness (all obtainable from guild traders in house K or from marketplace). They last long and don't cost much but they are true life-savers and don't take an equipment slot (no need for blindness immunity for example when a pot will do)
I agree on the pots, but disagree on Blindness Immunity item. When blinded in melee, it is pretty detrimental to have to quaff a pot while taking damage to get your sight back (only to get nailed by it again), than it is to be immune from the effects and have no interruption in your fight.
It is always smart to keep the pots around, but I would shoot for the immunity item as being what’s recommended.