actually, I find that it is much easier to climb hills on a fixie. A fixie forces you to continue pedaling, which forces you to maintain momentum. Even a momentary loss of momentum can cause you to stall when climbing a big hill.

as for gearing, go higher than you think you should. You'll have sore legs for a few days from climbing up hills, but the high gear will pay off when you aren't forced to pedal at 300 rpm down a hill.

I also suggest wide bullhorns so you can really crank your way up the hill.