Ideal Tool Kit

I have one of these, great basic tool kit, you can buy more specific tools, like a track chain whip as and when you need them

http://www.evanscycles.com/products/ice-toolz/essence-tool-kit-for-home-mechanics-ec006795

+1.. i don't really think the buy as you go is the best idea.. it turns out way more expensive than if you start with a basic kit like this and go from there.. unless you are a mechanic or building bikes all the time these tools will last fine ime