hi guys im new to all this and im looking for some advice. I have a Nikon d3100 with the 18 - 55 and 55-200 kit lenses but im now going to purchase the Sigma 150mm f/2.8 macro lens, to photograph my snakes and some insects(hopefully). Im guessing a flash will be a good investment. Any recommendations for flashes which will suit my purpose? i have £150, maybe £200 at a push. Thanks