Necro mage is the way to go imo. Many wrestle/scribe mages do very well, but I can never kill anyone with that "dueling" template. I run a nox/necro mage and love it. I tried scribe/necro, but I feel I make more of a difference with deadly fields in a grind, or just getting an omen/poison on someone.
I don't know how any mage can survive without magic resist. Once word gets out, you're vamped and sitting on the sidelines. It won't be hard to figure out either. One para test, and your secret is out. Plus every poison cast on you will stick.
You'll need 45 dci minimum, and a one handed sc no penalty wep so you can chug. This is tough to do because you no penalty weps that have dci 10 or better on them are big bucks. If you joined a faction though, it's quite easy because the folded steel glasses are 25 dci in factions. So folded's + armor of fort + quiver = 45 base dci.