Gear for incline - Internal Gear Hub? I'm new on the cycling scene and I'm looking to build a bike. I'm a bit worried about my route home, since although only 5KM it's quite steep in places, with 0.25KM being at a 16% incline, and the rest floating somewhere between 3-6%.

Start altitude: 14 metres 
End altitude: 99 metres 
Maximum altitude: 99 metres 
Minimum altitude: 11 metres 
Distance: 5 km 
Total ascent: 125 metres 
Total descent: 40 metres 
Maximum gradient ascending: 16% at 2.6 km 
Maximum gradient descending: 8% at 3.4 km 


I quite like the idea of an internal gear hub, but I'm wondering if that's a bad idea given the gradient and my lack of experience. Is it as simple as just using the pedal gear to vary the ratio going into the IGH, or is it a case that the IGH is simply not a sensible choice for this kind of gradient.
By using a larger sprocket and/or smaller chainring, you can gear an internal hub to cope with just about any gradient. (There is an eventual limit where input torque can destroy the hub.)

(Edit: @Rider_X is right that the Shimano limit is more restrictive than I remembered. There are people using lower gearing and reporting no problems, but you might have to be careful. On the comparison chart below the Rohloff could be geared quite a bit lower (30:16 rather than 44:16, see Rohloff), but the Nexus is following Shimano recommendations according to this forum post))



A cheap hub will give you three gears with big gaps between them and a limited overall range, and although you can make the bottom gear low enough for a steep gradient you might find it too restrictive; a very expensive Rohloff hub will give you 14 gears with gaps and range comparable to a derailleur system (but without overlapping or duplicate gears - a 27-speed derailleur system doesn't have 27 usefully different gears).
In between those, there's a range of hubs available giving you more gears, more overall range, and smaller gaps, as you pay more. See, for example:


http://www.cyclinguk.org/cyclists-library/components/transmission-gears/internal-gear/internal-gear-ratios
https://hubstripping.wordpress.com/internal-gear-hub-review/