[Jarkko]

My choice for MA Ulm pretender currently with CBM would be a Great Sage with rainbow paths (preferably with F3W2(and the rest at 1 or 2) so that you can craft a staff of elements later on with the help of RoW and other and a water or earth booster (plus the runic hammer for some penetration goodness) and the ability to cast Strands of Arcane Power. You'll want to research Evocation anyway for the Iron Blizzard, and you'll get SoAP up as a collateral thing. SoAP will accomplish two things:
1) More special sites (hopefully with varied mages)
2) You'll be even less of a prefered target for a mid-game war (although once people figure out you have Iron Darts (not to mention Iron Blizzard) tends to make them think twice if it is *really* worthwhile to attack Ulm)

Sure, one could say it depends lots on luck (that you will find some good sites with SoAP), but even if you found just some gem sites, it would still allow your Great Sage to utilise the rainbow paths.