Improving sustain and eHP is where I would go, can get some more dps on the way :)
It depends on how your character is balanced, but typically 1 all resist = 1 vit give or take. around 650 AR and 45k life they're about even I think, which are good goals for high mp's.
Inna's pants with 150+ vit is a better option than AR.
Trade the zuni ring in for something with a xx-xx avg damage roll, 8+ apsd, 5+ crit plus maybe survivability/loh.
Nat's boots with double resist, or AR/vit.
I'm not a big fan of inna's belt, but you have two black weapons I suppose. Could try looking for a witching hour, has a higher ceiling for eHP, can also roll %life.
Tal's ammy should probably go, get a rare with 40+ average damage, 9+ crit chance, 50+ crit damage, dex + whatever quality of life you want (vit/loh/resists).
I'm not a fan of lacuni's, until you're really set up with eHP, or doing lower mp's. Get some rare's - 100+ dex/vit, high single or double resist, as much crit as you can afford.
Sustain wise, when I first started doing high mp's i had about 2.9% ls, 920 loh. Was pretty happy with that, I now have just 5.7% LS, which is better although I may try and get an extra 400ish LOH just to really lock it down. How you want to spread that across your weapon and gear, that's up to you.
profile for ideas.
EDIT: read your edit, needs moar all resist, crit hit damage (try and get it on weapons + open sockets if possible)
Edited by punisher#1922 on 1/25/2013 6:59 AM PST