Hi guys fairly new to the world of photography i have a nikon 5100 with a standard 18-55 lens, nikkor 50mm 1.8 and a tamron 70-300 tele macro 4-5.6. I run a bar and nightclub so i figure its the perfect place to learn how to take club photos with out worrying about making mistakes so I'm looking at buying a new lens maybe a sigma 24-70 2.8 or a sigma 17-50 2.8 and i will need a flash but they are kinda expensive but I'm looking at a nikon sb700 if any one has any thoughts or recommendation they would be grateful