My choice would be a 50mm f/1.4 or f/1.8 for portraits and a zoom lens in the 12-24mm range for landscapes. With all wide angle lenses I strongly suggest you read reviews and look for examples that show the distortion levels and any light falloff, distortion can completely ruin a photo especially if it has straight lines in it (such as the horizon or buildings). You'll probably find you get what you pay for.
I also suggest you look at
www.bhphotovideo.com for prices. I've bought heaps of camera gear and lenses from them and they are usually at least 30% cheaper than the best Australian prices.