I like shoulder bags. The Lowepro Rezo 160 AW is too small, and the Rezo 190 AW has room to spare for that combo, so something in between (if it exists) would be ideal.
The 160 would hold the camera (just) and two lenses, but not the flash. The 190 would hold everything twice.
_________________Canon DSLRs: 7D, 5D2, 1D, 600D, 450D full spectrum, 300D IR mod
Lenses: EF 35/2, 50/1.8, 85/1.8, 135/2+SF, 28-80 V, 70-300L, 100-400L, TS-E 24/3.5L, MP-E 65, EF-S 15-85 IS
3rd party: Zeiss 2/50 makro, Samyang 8mm fisheye, Sigma 150 macro, 120-300 f/2.8 OS, Celestron 1325/13
Tinies: Sony HX9V.