At 67 you should be more than fine to kill them. I dont really udnerstand what is the issue. Even by maxing holy freeze which is your build with main synergy in resist cold, you should be able to kill them. Are you going at them under /players 8 or something?
If you go to akara NM, keep checking her store (go in and out of town to respawn offer) untill she has wand with life tap charges. You can use it on switch on ancients and keep casting that curse on them and leech life from them. So can your merc.
I asume that you have Holy shield skill, if not, you should and of course skill Smite.
Idk what is your equip, and what you found. You certainly have some options.
You should be able to make these two runewords: base can be bought from Fara normal:
One has crushing blow so if you use smite on ancients, it will takeaways good portion of their life. Maybe you already found something else with crushing blow, so combining that would be best.
Open wounds from other weapon has open wound, if you hit monster and that is applied(they visible bleed) it will keep doing damage to them for certain period of time. So that helps also.
About magic find: its best to mf in act 5 NM as monsters have higher level and can drop better things generaly speaking.
You can also try hunting objects, its easy, just set game to /players 8 and keep running Lower kurast and click objects. It help help you to gear up.
Also you can visit my guide, there is plenty of info you can certainly use: I have some MF spoits on NM mentioned there too.
Can you maybe share what is your equip? and skill distribution?
I forgot runeword:
Black 3 Socket Clubs/Hammers/Maces Thul + Io + Nef
this has also quite high crushing blow. And is rather cheap.