The 50f1.8 should be better in low light (providing you can zoom with your feet). If the 3200 flash is like the 5100, it will only be good for fill. No where near the range of an SB28 or SB800 and the settings can be tricky so practice a little before a critical shot. Also practice with the D3200, more pixels show user error mo betta. The D3s focuses and shoots so fast that it is much more forgiving.