My favourite lens for wildlife is my Sigma 100-300mm f4. It is incredibly sharp (rivals the 70-200mm VR) and handles well. The zoom is also useful for framing. It will be a bit short though for birds although it works very well with the matching Sigma 1.4x TC.
Don’t waste money on inferior glass because it is cheaper – there is usually a good reason why it is cheaper. Rather save up until you can afford the glass you want.
You are welcome to come around sometime to see the lenses. Send me an email – I am quite close (Cowies Hill).