I love my kit lens, probably the most versatile lens ever, I regret selling it, but oh well.
You can't use a 50mm prime as a replacement, it's just not the same, get a Tamrom 28-75, or if you want to spend a bit more money, 16-35L or 17-40L wouldn't go astray either. The 17-85 IS is a good replacement for the kit lens as well.
Noise ninja is probably the reason it's so soft, what ISO were you using? If you stay below 800, the 300d is usually pretty good with noise.